Modeling in Scientific Research | Process of Science

<!DOCTYPE html> <html lang="en" dir="ltr"> <head>  <meta http-equiv="X-UA-Compatible" content="ie=edge"> <meta charset="utf-8"> <base href="https://www.visionlearning.com"> <title>Modeling in Scientific Research | Process of Science | Visionlearning</title> <link rel="canonical" href="https://www.visionlearning.com/en/library/process-of-science/49/modeling-in-scientific-research/153"> <meta name="description" content="Learn how modeling is used as a scientific research method. Includes information on conceptual and physical models, as well as principles scientists use when creating them."> <meta name="keywords" content="modeling techniques in research, Basic research methods, Examples of model research methods, Scientific methodologies"> <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no"> <meta name="msvalidate.01" content="D8E20F39AD48052260032E56DE409970"> <script type="application/ld+json"> { "@context": "http://schema.org/", "@type": "Article", "mainEntityOfPage": { "@type": "WebPage", "@id": "https://visionlearning.com/en/library/process-of-science/49/modeling-in-scientific-research/153" }, "name": "Modeling in Scientific Research", "headline": "Modeling in Scientific Research: Simplifying a system to make predictions", "author": [ { "@type": "Person", "name": "Anne E. Egger, Ph.D." } , { "@type": "Person", "name": "Anthony Carpi, Ph.D." }], "datePublished": "2008-12-23 08:15:11", "dateModified": "2017-02-12T08:30:00+05:00", "image": { "@type": "ImageObject", "url": "/img/library/moduleImages/featured_image_153-23061210061449.jpg", "width": 696, "height": 464 }, "publisher": { "@type": "Organization", "name": "Visionlearning, Inc.", "logo": { "@type": "ImageObject", "url": "http://visionlearning.com/images/logo.png", "width": 278, "height": 60 } }, "description": "Scientific modeling is a research method scientists use to replicate real-world systems-whether it's a conceptual model of an atom, a physical model of a river delta, or a computer model of global climate. This module describes the principles that scientists use when building models and shows how modeling contributes to the process of science.", "keywords": "modeling techniques in research, Basic research methods, Examples of model research methods, Scientific methodologies", "inLanguage": { "@type": "Language", "name": "English", "alternateName": "en" }, "copyrightHolder": { "@type": "Organization", "name": "Visionlearning, Inc." }, "copyrightYear": "2008"} </script> <meta property="og:url" content="https://visionlearning.com/en/library/process-of-science/49/modeling-in-scientific-research/153"> <meta property="og:title" content="Modeling in Scientific Research | Process of Science | Visionlearning" /> <meta property="og:type" content="website"> <meta property="og:site_name" content="Visionlearning"> <meta property="og:description" content="Learn how modeling is used as a scientific research method. 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<li><a href="/en/library/earth-science/6/factors-that-control-earths-temperature/234">Factors that Control Earth's Temperature</a></li> <li><a href="/en/library/earth-science/6/circulation-in-the-atmosphere/255">Circulation in the Atmosphere</a></li> </ul> </div> <button class="accordion__button" id="acc-button-hazards" data-accordion="button" aria-controls="acc-panel-hazards" aria-expanded="false"> <span class="accordion__button__label"> Hazards </span> </button> <div class="accordion__panel" id="acc-panel-hazards" data-accordion="panel" aria-labelledby="acc-button-hazards" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/earth-science/6/natural-hazards-and-risk/288">Natural Hazards and Risk</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-history" data-accordion="button" aria-controls="acc-panel-earth-history" aria-expanded="false"> <span class="accordion__button__label"> Earth History </span> </button> <div class="accordion__panel" 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aria-controls="acc-panel-ecology" aria-expanded="false"> <span class="accordion__button__label"> Ecology </span> </button> <div class="accordion__panel" id="acc-panel-ecology" data-accordion="panel" aria-labelledby="acc-button-ecology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/biodiversity-i/276">Biodiversity I</a></li> <li><a href="/en/library/environmental-science/61/biodiversity-ii/281">Biodiversity II</a></li> <li><a href="/en/library/environmental-science/61/ecosystem-services/279">Ecosystem Services</a></li> <li><a href="/en/library/environmental-science/61/population-biology/287">Population Biology</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-cycles" data-accordion="button" aria-controls="acc-panel-earth-cycles" aria-expanded="false"> <span class="accordion__button__label"> Earth Cycles </span> </button> <div class="accordion__panel" id="acc-panel-earth-cycles" data-accordion="panel" aria-labelledby="acc-button-earth-cycles" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/the-nitrogen-cycle/98">The Nitrogen Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-carbon-cycle/95">The Carbon Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-phosphorus-cycle/197">The Phosphorus Cycle</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/environmental-science/61/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-general-science" data-accordion="button" aria-controls="acc-panel-general-science" aria-expanded="false"> <span class="accordion__button__label"> General Science </span> </button> <div class="accordion__panel" id="acc-panel-general-science" data-accordion="panel" aria-labelledby="acc-button-general-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-methods" data-accordion="button" aria-controls="acc-panel-methods" aria-expanded="false"> <span class="accordion__button__label"> Methods </span> </button> <div class="accordion__panel" id="acc-panel-methods" data-accordion="panel" aria-labelledby="acc-button-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-scientific-method/45">The Scientific Method</a></li> </ul> </div> <button class="accordion__button" id="acc-button-measurement" data-accordion="button" aria-controls="acc-panel-measurement" aria-expanded="false"> <span class="accordion__button__label"> Measurement </span> </button> <div class="accordion__panel" id="acc-panel-measurement" data-accordion="panel" aria-labelledby="acc-button-measurement" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-metric-system/47">The Metric System</a></li> </ul> </div> <button class="accordion__button" id="acc-button-physical-properties" data-accordion="button" aria-controls="acc-panel-physical-properties" aria-expanded="false"> <span class="accordion__button__label"> Physical Properties </span> </button> <div class="accordion__panel" id="acc-panel-physical-properties" data-accordion="panel" aria-labelledby="acc-button-physical-properties" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/temperature/48">Temperature</a></li> <li><a href="/en/library/general-science/3/density-and-buoyancy/37">Density and Buoyancy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-math-in-science" data-accordion="button" aria-controls="acc-panel-math-in-science" aria-expanded="false"> <span class="accordion__button__label"> Math in Science </span> </button> <div class="accordion__panel" id="acc-panel-math-in-science" data-accordion="panel" aria-labelledby="acc-button-math-in-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-equations" data-accordion="button" aria-controls="acc-panel-equations" aria-expanded="false"> <span class="accordion__button__label"> Equations </span> </button> <div class="accordion__panel" id="acc-panel-equations" data-accordion="panel" aria-labelledby="acc-button-equations" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/unit-conversion/144">Unit Conversion</a></li> <li><a href="/en/library/math-in-science/62/linear-equations/194">Linear Equations</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-i/206">Exponential Equations I</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-ii/210">Exponential Equations II</a></li> <li><a href="/en/library/math-in-science/62/scientific-notation/250">Scientific Notation</a></li> <li><a href="/en/library/math-in-science/62/measurement/257">Measurement</a></li> </ul> </div> <button class="accordion__button" id="acc-button-statistics" data-accordion="button" aria-controls="acc-panel-statistics" aria-expanded="false"> <span class="accordion__button__label"> Statistics </span> </button> <div class="accordion__panel" id="acc-panel-statistics" data-accordion="panel" aria-labelledby="acc-button-statistics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/introduction-to-descriptive-statistics/218">Introduction to Descriptive Statistics</a></li> <li><a href="/en/library/math-in-science/62/introduction-to-inferential-statistics/224">Introduction to Inferential Statistics</a></li> <li><a href="/en/library/math-in-science/62/statistical-techniques/239">Statistical Techniques</a></li> </ul> </div> <button class="accordion__button" id="acc-button-trigonometric-functions" data-accordion="button" aria-controls="acc-panel-trigonometric-functions" aria-expanded="false"> <span class="accordion__button__label"> Trigonometric Functions </span> </button> <div class="accordion__panel" id="acc-panel-trigonometric-functions" data-accordion="panel" aria-labelledby="acc-button-trigonometric-functions" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/wave-mathematics/131">Wave Mathematics</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-physics" data-accordion="button" aria-controls="acc-panel-physics" aria-expanded="false"> <span class="accordion__button__label"> Physics </span> </button> <div class="accordion__panel" id="acc-panel-physics" data-accordion="panel" aria-labelledby="acc-button-physics" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-light-and-optics" data-accordion="button" aria-controls="acc-panel-light-and-optics" aria-expanded="false"> <span class="accordion__button__label"> Light and Optics </span> </button> <div class="accordion__panel" id="acc-panel-light-and-optics" data-accordion="panel" aria-labelledby="acc-button-light-and-optics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/the-nature-of-light/132">The Nature of Light</a></li> <li><a href="/en/library/physics/24/electromagnetism-and-light/138">Electromagnetism and Light</a></li> </ul> </div> <button class="accordion__button" id="acc-button-mechanics" data-accordion="button" aria-controls="acc-panel-mechanics" aria-expanded="false"> <span class="accordion__button__label"> Mechanics </span> </button> <div class="accordion__panel" id="acc-panel-mechanics" data-accordion="panel" aria-labelledby="acc-button-mechanics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/defining-energy/199">Defining Energy</a></li> <li><a href="/en/library/physics/24/waves-and-wave-motion/102">Waves and Wave Motion</a></li> <li><a href="/en/library/physics/24/gravity/118">Gravity</a></li> <li><a href="/en/library/physics/24/thermodynamics-i/200">Thermodynamics I</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-process-of-science" data-accordion="button" aria-controls="acc-panel-process-of-science" aria-expanded="false"> <span class="accordion__button__label"> Process of Science </span> </button> <div class="accordion__panel" id="acc-panel-process-of-science" data-accordion="panel" aria-labelledby="acc-button-process-of-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-introduction" data-accordion="button" aria-controls="acc-panel-introduction" aria-expanded="false"> <span class="accordion__button__label"> Introduction </span> </button> <div class="accordion__panel" id="acc-panel-introduction" data-accordion="panel" aria-labelledby="acc-button-introduction" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-process-of-science/176">The Process of Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-the-culture-of-science" data-accordion="button" aria-controls="acc-panel-the-culture-of-science" aria-expanded="false"> <span class="accordion__button__label"> The Culture of Science </span> </button> <div class="accordion__panel" id="acc-panel-the-culture-of-science" data-accordion="panel" aria-labelledby="acc-button-the-culture-of-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-nature-of-scientific-knowledge/185">The Nature of Scientific Knowledge</a></li> <li><a href="/en/library/process-of-science/49/scientists-and-the-scientific-community/172">Scientists and the Scientific Community</a></li> <li><a href="/en/library/process-of-science/49/scientific-ethics/161">Scientific Ethics</a></li> <li><a href="/en/library/process-of-science/49/scientific-institutions-and-societies/162">Scientific Institutions and Societies</a></li> </ul> </div> <button class="accordion__button" id="acc-button-ideas-in-science" data-accordion="button" aria-controls="acc-panel-ideas-in-science" aria-expanded="false"> <span class="accordion__button__label"> Ideas in Science </span> </button> <div class="accordion__panel" id="acc-panel-ideas-in-science" data-accordion="panel" aria-labelledby="acc-button-ideas-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/theories-hypotheses-and-laws/177">Theories, Hypotheses, and Laws</a></li> <li><a href="/en/library/process-of-science/49/scientific-controversy/181">Scientific Controversy</a></li> <li><a href="/en/library/process-of-science/49/creativity-in-science/182">Creativity in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-research-methods" data-accordion="button" aria-controls="acc-panel-research-methods" aria-expanded="false"> <span class="accordion__button__label"> Research Methods </span> </button> <div class="accordion__panel" id="acc-panel-research-methods" data-accordion="panel" aria-labelledby="acc-button-research-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-practice-of-science/148">The Practice of Science</a></li> <li><a href="/en/library/process-of-science/49/experimentation-in-scientific-research/150">Experimentation in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/description-in-scientific-research/151">Description in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/comparison-in-scientific-research/152">Comparison in Scientific Research</a></li> <li class="current">Modeling in Scientific Research</li> </ul> </div> <button class="accordion__button" id="acc-button-data" data-accordion="button" aria-controls="acc-panel-data" aria-expanded="false"> <span class="accordion__button__label"> Data </span> </button> <div class="accordion__panel" id="acc-panel-data" data-accordion="panel" aria-labelledby="acc-button-data" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/data-analysis-and-interpretation/154">Data Analysis and Interpretation</a></li> <li><a href="/en/library/process-of-science/49/uncertainty-error-and-confidence/157">Uncertainty, Error, and Confidence</a></li> <li><a href="/en/library/process-of-science/49/statistics-in-science/155">Statistics in Science</a></li> <li><a href="/en/library/process-of-science/49/using-graphs-and-visual-data-in-science/156">Using Graphs and Visual Data in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-communication" data-accordion="button" aria-controls="acc-panel-scientific-communication" aria-expanded="false"> <span class="accordion__button__label"> Scientific Communication </span> </button> <div class="accordion__panel" id="acc-panel-scientific-communication" data-accordion="panel" aria-labelledby="acc-button-scientific-communication" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/understanding-scientific-journals-and-articles/158">Understanding Scientific Journals and Articles</a></li> <li><a href="/en/library/process-of-science/49/utilizing-the-scientific-literature/173">Utilizing the Scientific Literature</a></li> <li><a href="/en/library/process-of-science/49/peer-review-in-scientific-publishing/159">Peer Review in Scientific Publishing</a></li> <li><a href="/en/library/process-of-science/49/the-how-and-why-of-scientific-meetings/186">The How and Why of Scientific Meetings</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-scientists-and-research" data-accordion="button" aria-controls="acc-panel-scientists-and-research" aria-expanded="false"> <span class="accordion__button__label"> Scientists and Research </span> </button> <div class="accordion__panel" id="acc-panel-scientists-and-research" data-accordion="panel" aria-labelledby="acc-button-scientists-and-research" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/scientists-and-research/58/from-stable-chromosomes-to-jumping-genes/184">From Stable Chromosomes to Jumping Genes</a></li> <li><a href="/en/library/scientists-and-research/58/an-elegant-experiment-to-test-the-process-of-dna-replication/187">An Elegant Experiment to Test the Process of DNA Replication</a></li> <li><a href="/en/library/scientists-and-research/58/the-founding-of-neuroscience/233">The Founding of Neuroscience</a></li> <li><a href="/en/library/scientists-and-research/58/tracking-endangered-jaguars-across-the-border/189">Tracking Endangered Jaguars across the Border</a></li> <li><a href="/en/library/scientists-and-research/58/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> <li><a href="/en/library/scientists-and-research/58/revolutionizing-medicine-with-monoclonal-antibodies/220">Revolutionizing Medicine with Monoclonal Antibodies</a></li> <li><a href="/en/library/scientists-and-research/58/uncovering-the-mysteries-of-chronic-mountain-sickness/238">Uncovering the Mysteries of Chronic Mountain Sickness</a></li> </ul> </div> <button class="accordion__button" id="acc-button-profiles-in-science" data-accordion="button" aria-controls="acc-panel-profiles-in-science" aria-expanded="false"> <span class="accordion__button__label"> Profiles in Science </span> </button> <div class="accordion__panel" id="acc-panel-profiles-in-science" data-accordion="panel" aria-labelledby="acc-button-profiles-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/luis-e.-miramontes/232">Luis E. Miramontes</a></li> <li><a href="/en/library/scientists-and-research/58/bernardo-houssay/237">Bernardo Houssay</a></li> <li><a href="/en/library/scientists-and-research/58/craig-lee/256">Craig Lee</a></li> <li><a href="/en/library/scientists-and-research/58/david-ho/241">David Ho</a></li> <li><a href="/en/library/scientists-and-research/58/louis-tompkins-wright/244">Louis Tompkins Wright</a></li> <li><a href="/en/library/scientists-and-research/58/carlos-j.-finlay/217">Carlos J. Finlay</a></li> <li><a href="/en/library/scientists-and-research/58/cecilia-payne/290">Cecilia Payne</a></li> <li><a href="/en/library/scientists-and-research/58/jazmin-scarlett/291">Jazmin Scarlett</a></li> <li><a href="/en/library/scientists-and-research/58/ramari-stewart/292">Ramari Stewart</a></li> <li><a href="/en/library/scientists-and-research/58/johnson-cerda/300">Johnson Cerda</a></li> <li><a href="/en/library/scientists-and-research/58/ellen-ochoa/201">Ellen Ochoa</a></li> <li><a href="/en/library/scientists-and-research/58/ruth-benerito/205">Ruth Benerito</a></li> <li><a href="/en/library/scientists-and-research/58/franklin-chang-díaz/219">Franklin Chang Díaz</a></li> <li><a href="/en/library/scientists-and-research/58/percy-lavon-julian/221">Percy Lavon Julian</a></li> <li><a href="/en/library/scientists-and-research/58/luis-walter-alvarez/229">Luis Walter Alvarez</a></li> <li><a href="/en/library/scientists-and-research/58/france-anne-dominic-córdova/230">France Anne-Dominic Córdova</a></li> </ul> </div> </div> </div> </div> </div> </li> <li>  <button class="button" data-toggle="dropdown">Process of Science </button> <div class="nav__dropdown box-shadow-1 padding-1"> <div class="accordion accordion--secondary font-size-sm"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-sub-button-introduction" data-accordion="button" aria-controls="acc-sub-panel-introduction" aria-expanded="false"> <span class="accordion__button__label"> Introduction </span> </button> <div class="accordion__panel" id="acc-sub-panel-introduction" data-accordion="panel" aria-labelledby="acc-sub-button-introduction" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-process-of-science/176">The Process of Science</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-the-culture-of-science" data-accordion="button" aria-controls="acc-sub-panel-the-culture-of-science" aria-expanded="false"> <span class="accordion__button__label"> The Culture of Science </span> </button> <div class="accordion__panel" id="acc-sub-panel-the-culture-of-science" data-accordion="panel" aria-labelledby="acc-sub-button-the-culture-of-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-nature-of-scientific-knowledge/185">The Nature of Scientific Knowledge</a></li> <li><a href="/en/library/process-of-science/49/scientists-and-the-scientific-community/172">Scientists and the Scientific Community</a></li> <li><a href="/en/library/process-of-science/49/scientific-ethics/161">Scientific Ethics</a></li> <li><a href="/en/library/process-of-science/49/scientific-institutions-and-societies/162">Scientific Institutions and Societies</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-ideas-in-science" data-accordion="button" aria-controls="acc-sub-panel-ideas-in-science" aria-expanded="false"> <span class="accordion__button__label"> Ideas in Science </span> </button> <div class="accordion__panel" id="acc-sub-panel-ideas-in-science" data-accordion="panel" aria-labelledby="acc-sub-button-ideas-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/theories-hypotheses-and-laws/177">Theories, Hypotheses, and Laws</a></li> <li><a href="/en/library/process-of-science/49/scientific-controversy/181">Scientific Controversy</a></li> <li><a href="/en/library/process-of-science/49/creativity-in-science/182">Creativity in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-research-methods" data-accordion="button" aria-controls="acc-sub-panel-research-methods" aria-expanded="false"> <span class="accordion__button__label"> Research Methods </span> </button> <div class="accordion__panel" id="acc-sub-panel-research-methods" data-accordion="panel" aria-labelledby="acc-sub-button-research-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-practice-of-science/148">The Practice of Science</a></li> <li><a href="/en/library/process-of-science/49/experimentation-in-scientific-research/150">Experimentation in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/description-in-scientific-research/151">Description in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/comparison-in-scientific-research/152">Comparison in Scientific Research</a></li> <li class="current">Modeling in Scientific Research</li> </ul> </div> <button class="accordion__button" id="acc-sub-button-data" data-accordion="button" aria-controls="acc-sub-panel-data" aria-expanded="false"> <span class="accordion__button__label"> Data </span> </button> <div class="accordion__panel" id="acc-sub-panel-data" data-accordion="panel" aria-labelledby="acc-sub-button-data" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/data-analysis-and-interpretation/154">Data Analysis and Interpretation</a></li> <li><a href="/en/library/process-of-science/49/uncertainty-error-and-confidence/157">Uncertainty, Error, and Confidence</a></li> <li><a href="/en/library/process-of-science/49/statistics-in-science/155">Statistics in Science</a></li> <li><a href="/en/library/process-of-science/49/using-graphs-and-visual-data-in-science/156">Using Graphs and Visual Data in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-scientific-communication" data-accordion="button" aria-controls="acc-sub-panel-scientific-communication" aria-expanded="false"> <span class="accordion__button__label"> Scientific Communication </span> </button> <div class="accordion__panel" id="acc-sub-panel-scientific-communication" data-accordion="panel" aria-labelledby="acc-sub-button-scientific-communication" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/understanding-scientific-journals-and-articles/158">Understanding Scientific Journals and Articles</a></li> <li><a href="/en/library/process-of-science/49/utilizing-the-scientific-literature/173">Utilizing the Scientific Literature</a></li> <li><a href="/en/library/process-of-science/49/peer-review-in-scientific-publishing/159">Peer Review in Scientific Publishing</a></li> <li><a href="/en/library/process-of-science/49/the-how-and-why-of-scientific-meetings/186">The How and Why of Scientific Meetings</a></li> </ul> </div> </div> </div> </div> </li> </ul> </nav>  <div id="theTop"></div> <main id="skip-header-content"> <div class="margin-bottom-5"> <div class="container narrow wide--lg margin-y-4"> <article class="module"> <header class="module__header"> <span class="subcategory"> <strong><em>Research Methods</em></strong> </span> <h1>Modeling in Scientific Research: <sub><em>Simplifying a system to make predictions</em></sub></h1> <p class="byline">by Anne E. Egger, Ph.D., Anthony Carpi, Ph.D.</p> </header> <nav class="module__tabs"> <ul class="tabs-nav tabs-nav--pill tabs-nav--horizontal--md library"> <li> <a href="/en/library/process-of-science/49/modeling-in-scientific-research/153/reading" class="is-active" aria-current="page" >Reading</a> </li> <li> <a href="/en/library/process-of-science/49/modeling-in-scientific-research/153/quiz" >Quiz</a> </li> <li> <a href="/en/library/process-of-science/49/modeling-in-scientific-research/153/resources" >Teach with this</a> </li> </ul> </nav> <script type="application/ld+json"> { "@context": "http://schema.org", "@type": "AudioObject", "contentUrl": "https://www.visionlearning.com/img/library/moduleAudio/module_153.mp3", "description": "Recording of Modeling in Scientific Research : Scientific modeling is a research method scientists use to replicate real-world systems-whether it's a conceptual model of an atom, a physical model of a river delta, or a computer model of global climate. This module describes the principles that scientists use when building models and shows how modeling contributes to the process of science.", "encodingFormat": "mp3", "name": "module_153.mp3" } </script> <div class="module__audio"> <div class="audio-player border border-radius"> <audio id="audio"> <source src="https://www.visionlearning.com/img/library/moduleAudio/module_153.mp3" type="audio/mpeg"> Your browser does not support the audio element. </audio> <div class="audio-player__title"> <p>Listen to this reading</p> <span class="audio-player__timestamp" id="timestamp"> 00:00 </span> </div> <div class="audio-player__controls" id="controls"> <button class="button button--icon-only" id="play-pause-button"> <span class="icon icon-play" aria-hidden="true"></span> </button> <div class="audio-player__progress" id="progress-bar" tabindex="0" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0" aria-label="Use arrow keys to forward or rewind the audio" role="slider"> <div class="audio-player__progress__fill"> <span class="audio-player__thumb"></span> </div> </div> <div class="audio-player__volume-container"> <button id="mute-button"> <span class="icon icon-volume"></span> </button> <div class="audio-player__volume" tabindex="0" aria-valuemin="0" aria-valuemax="100" aria-valuenow="100" aria-label="Use arrow keys to adjust volume" role="slider"> <div class="audio-player__volume__fill"> <span class="audio-player__thumb"></span> </div> </div> </div> </div> </div> </div> <hr class="module__divider" />  <div class="module__tools"> <aside class="module__tools__container border-radius box-shadow-1"> <div class="tabs tabs--toggle-mobile--lg" role="tablist"> <ul class="tab__buttons"> <li> <button class="button button--icon-over-text" aria-label="In this module" aria-controls="tab-panel-module__tools" aria-selected="true" role="tab"> <span class="button__icon"> <span class="icon icon-list" aria-hidden="true"></span> </span> <span class="button__text">Contents</span> </button> </li> <li> <button class="button button--icon-over-text" aria-controls="tab-panel-toggle-terms" aria-selected="false" role="tab"> <span class="button__icon"> <span class="icon icon-glossary-highlight"></span> </span> <span class="button__text">Glossary Terms</span> </button> </li> <li> <button class="button button--icon-over-text" aria-controls="tab-panel-toggle-ngss" aria-selected="false" role="tab"> <span class="button__icon"> <span class="icon icon-ngss" aria-hidden="true"></span> </span> <span class="button__text">NGSS</span> </button> </li> </ul> <div class="tabs__panel shown" id="tab-panel-module__tools" aria-labelledby="tab-button-module__tools" role="tabpanel"> <div class="table-of-contents"> <p class="table-of-contents__title"> Table of Contents </p> <ul class="table-of-contents__nav"> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_1">Types of models: Physical, conceptual, mathematical</a> </li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_2">Modeling as a scientific research method</a> </li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_3">The beginning of computer modeling: Numerical weather prediction</a> </li> <li> <ul> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc2_1">Using calculations predictively</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc2_2">Advancing weather calculations</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc2_3">First computer for weather prediction</a> </li> </ul> </li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_4">Modeling in practice: The development of global climate models</a> </li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_5">Limitations and misconceptions of models</a> </li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153#toc_6">Modeling in modern practice</a> </li> </ul> </div> </div> <div class="tabs__panel" id="tab-panel-toggle-terms" aria-labelledby="tab-button-toggle-terms" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="termsToggleSwitch" id="terms-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Highlight Glossary Terms </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate glossary term highlighting to easily identify key terms within the module. Once highlighted, you can click on these terms to view their definitions. </em> </p> </div> </div> <div class="glossary-container"></div> </div> <div class="tabs__panel" id="tab-panel-toggle-ngss" aria-labelledby="tab-button-toggle-ngss" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="ngssToggleSwitch" id="ngss-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Show NGSS Annotations </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate NGSS annotations to easily identify NGSS standards within the module. Once highlighted, you can click on them to view these standards. </em> </p> </div> </div> <div class="ngss-container"></div> </div> </div> </aside> <div class="margin-3"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-9561344156007092" data-ad-slot="7634263342" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </div>     <div class="module__main"> <div class="module__main__container"> <div class="accordion">  <button class="accordion__button" id="acc-button-key-concepts" data-accordion="button" aria-controls="acc-panel-key-concepts" aria-expanded="true" tabindex="0"> Did you know? </button> <div class="accordion__panel shown show" id="acc-panel-key-concepts" data-accordion="panel" aria-labelledby="acc-button-key-concepts" role="region"> <div class="accordion__panel__content"> <p>Did you know that scientific models can help us peer inside the tiniest atom or examine the entire universe in a single glance? Models allow scientists to study things too small to see, and begin to understand things too complex to imagine.</p> </div> </div>  <button class="accordion__button" id="acc-button-table-of-contents" data-accordion="button" aria-controls="acc-panel-table-of-contents" aria-expanded="false" tabindex="0"> Key concepts </button> <div class="accordion__panel" id="acc-panel-table-of-contents" data-accordion="panel" aria-labelledby="acc-button-table-of-contents" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <ul class="bulleted"> <li><p>Modeling involves developing physical, conceptual, or computer-based representations of systems.</p></li> <li><p>Scientists build models to replicate systems in the real world through simplification, to perform an experiment that cannot be done in the real world, or to assemble several known ideas into a coherent whole to build and test hypotheses.</p></li> <li><p>Computer modeling is a relatively new scientific research method, but it is based on the same principles as physical and conceptual modeling.</p></li> </ul> </div> </div>  <button class="accordion__button" id="acc-button-terms-you-should-know" data-accordion="button" aria-controls="acc-panel-terms-you-should-know" aria-expanded="false" tabindex="0"> Terms you should know </button> <div class="accordion__panel" id="acc-panel-terms-you-should-know" data-accordion="panel" aria-labelledby="acc-button-terms-you-should-know" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <dl> <dt>conceptual </dt> <dd> relating to an idea rather than to a physical object. A <i>conceptual</i> module expresses an idea about how a system works. </dd> <dt><a href="/en/glossary/view/model">model </a></dt> <dd> a representation, pattern, or mathematical description that can help scientists replicate a system </dd> <dt><a href="/en/glossary/view/system">system </a></dt> <dd> a group of related parts that work together to form a whole. Examples of <i>systems</i> include an atom, a cell, a river delta, or a planet.</dd> </dl> </div> </div> </div> <section> <p>LEGO<sup>®</sup> bricks have been a staple of the toy world since they were first manufactured in Denmark in 1953. The interlocking plastic bricks can be assembled into an endless variety of objects (see Figure 1). Some kids (and even many adults) are interested in building the perfect <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> – finding the bricks of the right color, shape, and size, and assembling them into a replica of a familiar object in the real world, like a castle, the <mark class="term" data-term="space shuttle" data-term-def="A spacecraft that carries people and cargo between Earth and outer space." data-term-url="/en/glossary/view/space+shuttle/8751">space shuttle</mark>, or London Bridge. Others focus on using the object they build – moving LEGO knights in and out of the castle shown in Figure 1, for example, or enacting a space shuttle mission to Mars. Still others may have no particular end product in mind when they start snapping bricks together and just want to see what they can do with the pieces they have.</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_10088.png" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-10088-160704040750.png" alt="Figure 1: On the left, individual LEGO® bricks. On the right, a model of a NASA space center built with LEGO bricks." /> </button> <figcaption> <p><strong>Figure 1</strong>: On the left, individual LEGO® bricks. On the right, a model of a NASA space center built with LEGO bricks.</p> </figcaption> </figure> </div> <p>On the most basic level, scientists use <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> in much the same way that people play with LEGO bricks. Scientific models may or may not be physical entities, but scientists build them for the same variety of reasons: to replicate <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">systems</mark> in the real world through simplification, to perform an <mark class="term" data-term="experiment" data-term-def="A test or trial carried out under controlled conditions so that specific actions can be performed and the results can be observed." data-term-url="/en/glossary/view/experiment/8292">experiment</mark> that cannot be done in the real world, or to assemble several known ideas into a coherent whole to build and test <mark class="term" data-term="hypothesis" data-term-url="/en/glossary/view/hypothesis" data-term-def="From the Greek word <em>hypothesis</em> meaning assumption or the basis of an argument, a hypothesis is a proposal intended to explain&hellip;">hypotheses</mark>. </p> <p><section id="toc_1" class=""> <h2>Types of models: Physical, conceptual, mathematical</h2></p> <p><mark id="ngss-86" class="ngss"> At the St. Anthony Falls Laboratory at the University of Minnesota, a group of engineers and geologists have built a room-sized physical replica of a river <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark> to <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> a real one like the Mississippi River delta in the Gulf of Mexico (Paola et al., 2001). These researchers have successfully incorporated into their model the key processes that control river deltas (like the variability of water flow, the deposition of <mark class="term" data-term="sediment" data-term-def="Loose, unconsolidated material of the following compositions: <br> 1. rock fragments (also called clasts) transported by wind, moving water,&hellip;" data-term-url="/en/glossary/view/sediment/3310">sediments</mark> transported by the river, and the compaction and subsidence of the coastline under the pressure of constant sediment additions) in order to better understand how those processes interact. With their physical model, they can mimic the general setting of the Mississippi River delta and then do things they can't do in the real world, like take a slice through the resulting <mark class="term" data-term="sedimentary" data-term-def="Formed from the deposition or precipitation of sediments. Sedimentary rocks consist of sediments that have been compacted and cemented together." data-term-url="/en/glossary/view/sedimentary/3311">sedimentary</mark> deposits to analyze the layers within the sediments. Or they can <mark class="term" data-term="experiment" data-term-def="A test or trial carried out under controlled conditions so that specific actions can be performed and the results can be observed." data-term-url="/en/glossary/view/experiment/8292">experiment</mark> with changing <mark class="term" data-term="parameter" data-term-def="In statistics, a parameter is a numerical value that represents a characteristic of a statistical population. Contrast with statistic." data-term-url="/en/glossary/view/parameter/9481">parameters</mark> like sea level and sedimentary input to see how those changes affect deposition of sediments within the delta,</mark> the same way you might "experiment" with the placement of the knights in your LEGO castle.</p> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="9090201191"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_10087.png" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-10087-160704040719.png" alt="Figure 2: A photograph of the St. Anthony Falls lab river delta model, showing the experimental setup with pink-tinted water flowing over sediments. Image courtesy the National Center for Earth-Surface Dynamics Data Repository http://www.nced.umn.edu [accessed September, 2008]" /> </button> <figcaption> <p><strong>Figure 2</strong>: A photograph of the St. Anthony Falls lab river delta model, showing the experimental setup with pink-tinted water flowing over sediments. Image courtesy the National Center for Earth-Surface Dynamics Data Repository http://www.nced.umn.edu [accessed September, 2008]</p> <span class="credit">image ©National Center for Earth-surface Dynamics Data Repository</span> </figcaption> </figure> </div> <p>Not all <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> used in scientific <mark class="term" data-term="research" data-term-def="A study or an investigation." data-term-url="/en/glossary/view/research/8257">research</mark> are physical models. Some are conceptual, and involve assembling all of the known components of a <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark> into a coherent whole. This is a little like building an <mark class="term" data-term="abstract" data-term-def="In science, an abstract is a brief statement of essential information contained within a document or presentation. An abstract is not&hellip;" data-term-url="/en/glossary/view/abstract/5214">abstract</mark> sculpture out of LEGO bricks rather than building a castle. For example, over the past several hundred years, scientists have developed a series of models for the structure of an <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atom</mark>. <mark id="ngss-87" class="ngss">The earliest known model of the atom compared it to a billiard ball, reflecting what scientists knew at the time – they were the smallest piece of an <mark class="term" data-term="element" data-term-def="One of fewer than 118 pure chemical substances. An element is a substance composed of atoms with identical atomic number." data-term-url="/en/glossary/view/element/1510">element</mark> that maintained the properties of that element. Despite the fact that this was a purely conceptual model, it could be used to predict some of the behavior that atoms exhibit. However, it did not explain all of the properties of atoms accurately. With the discovery of subatomic <mark class="term" data-term="particle" data-term-def="A tiny piece of matter." data-term-url="/en/glossary/view/particle/8259">particles</mark> like the <mark class="term" data-term="proton" data-term-def="A subatomic (ß link to atom) particle with a positive charge of 1.60 × 10<sup>-19</sup> coulombs and a mass of 1.672&hellip;" data-term-url="/en/glossary/view/proton/854">proton</mark> and <mark class="term" data-term="electron" data-term-def="A subatomic particle with a negative charge of 1.60 × 10<sup>-19</sup> coulombs and a mass of 9.11 × 10<sup>-31</sup> kg. Electrons&hellip;" data-term-url="/en/glossary/view/electron/852">electron</mark>, the physicist <mark class="term" data-term="Ernest Rutherford" data-term-def="New Zealand-English physicist born in Nelson, New Zealand (1871-1937). Rutherford classified radiation into three types: alpha, beta, and gamma ray. In&hellip;" data-term-url="/en/glossary/view/Rutherford%2C+Ernest/4520">Ernest Rutherford</mark> proposed a "solar system" model of the atom, in which electrons orbited around a <mark class="term" data-term="nucleus" data-term-def="1. [Atomic] A tiny, dense positively charged mass at the heart of an atom. The nucleus is composed of protons and&hellip;" data-term-url="/en/glossary/view/nucleus/1526">nucleus</mark> that included protons (see our <a href="/library/module_viewer.php?mid=50">Atomic Theory I: The Early Days</a> module for more information). While the Rutherford model is useful for understanding basic properties of atoms, it eventually proved insufficient to explain all of the behavior of atoms. The current quantum model of the atom depicts electrons not as pure particles, but as having the properties of both particles and <mark class="term" data-term="waves" data-term-def="The motion of rising and falling in curves; undulation." data-term-url="/en/glossary/view/waves/8274">waves</mark>, and these electrons are located in specific <mark class="term" data-term="probability" data-term-def="The likelihood that a given event will occur. In statistics, probability is often expressed as a ratio of the number of&hellip;" data-term-url="/en/glossary/view/probability/3913">probability</mark> <mark class="term" data-term="density" data-term-def="A measure of the compactness of a substance given by the mass per unit volume (d = m/v). Common units of&hellip;" data-term-url="/en/glossary/view/density/863">density</mark> clouds around the atom's nucleus.</mark></p><p>Both physical and conceptual <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> continue to be important components of scientific <mark class="term" data-term="research" data-term-def="A study or an investigation." data-term-url="/en/glossary/view/research/8257">research</mark>. In addition, many scientists now build models mathematically through computer programming. These computer-based models serve many of the same purposes as physical models, but are determined entirely by mathematical relationships between <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> that are defined numerically. The mathematical relationships are kind of like individual LEGO bricks: They are basic building blocks that can be assembled in many different ways. In this case, the building blocks are fundamental concepts and <mark class="term" data-term="theory" data-term-url="/en/glossary/view/theory" data-term-def="A scientific theory is an explanation inferred from multiple lines of evidence for some broad aspect of the natural world and&hellip;">theories</mark> like the mathematical description of turbulent flow in a <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark>, the law of conservation of energy, or the laws of thermodynamics, which can be assembled into a wide variety of models for, say, the flow of contaminants released into a <mark class="term" data-term="groundwater" data-term-def="Water that fills pore space in rocks and sediments and forms a subsurface aquifer. Groundwater is distinct from soil moisture, which&hellip;" data-term-url="/en/glossary/view/groundwater/2119">groundwater</mark> reservoir or for global <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> change.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form name="cc5863"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">All models are exact replicas of physical things.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-5863-0-option-a" name="quiz-option-5863" type="radio" value="true" > <span class="option__label"> <span class="screen-reader-only">a.</span> true </span> </label> <span class="quiz__response" id="response-5863-0"> <strong>Incorrect.</strong> </span> </div> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-5863-1-option-b" name="quiz-option-5863" type="radio" value="false" > <span class="option__label"> <span class="screen-reader-only">b.</span> false </span> </label> <span class="quiz__response" id="response-5863-1"> <strong>Correct!</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_2"> <h2>Modeling as a scientific research method</h2><p>Whether developing a conceptual <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> like the atomic model, a physical model like a miniature river <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark>, or a computer model like a global <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> model, the first step is to define the <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark> that is to be modeled and the goals for the model. "System" is a generic term that can apply to something very small (like a single atom), something very large (like the Earth's atmosphere), or something in between, like the distribution of <mark class="term" data-term="nutrient" data-term-def="A chemical substance (e.g., minerals, vitamins, proteins) that is needed by an organism to survive and grow. See also: macronutrient and micronutrient." data-term-url="/en/glossary/view/nutrient/7058">nutrients</mark> in a local stream. So defining the system generally involves drawing the boundaries (literally or figuratively) around what you want to model, and then determining the key <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> and the relationships between those variables.</p><p>Though this initial step may seem straightforward, it can be quite complicated. Inevitably, there are many more <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> within a <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark> than can be realistically included in a <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark>, so scientists need to simplify. To do this, they make assumptions about which variables are most important. In building a physical model of a river <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark>, for example, the scientists made the assumption that biological processes like burrowing clams were not important to the large-scale structure of the delta, even though they are clearly a component of the real system. </p><p><mark id="ngss-88" class="ngss"> Determining where simplification is appropriate takes a detailed understanding of the real <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark> – and in fact, sometimes <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> are used to help determine exactly which aspects of the system can be simplified. For example, the scientists who built the model of the river <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark> did not incorporate burrowing clams into their model because they knew from experience that they would not affect the overall layering of <mark class="term" data-term="sediment" data-term-def="Loose, unconsolidated material of the following compositions: <br> 1. rock fragments (also called clasts) transported by wind, moving water,&hellip;" data-term-url="/en/glossary/view/sediment/3310">sediments</mark> within the delta. On the other hand, they were aware that vegetation strongly affects the shape of the river channel (and thus the distribution of sediments), and therefore conducted an <mark class="term" data-term="experiment" data-term-def="A test or trial carried out under controlled conditions so that specific actions can be performed and the results can be observed." data-term-url="/en/glossary/view/experiment/8292">experiment</mark> to determine the nature of the relationship between vegetation <mark class="term" data-term="density" data-term-def="A measure of the compactness of a substance given by the mass per unit volume (d = m/v). Common units of&hellip;" data-term-url="/en/glossary/view/density/863">density</mark> and river channel shape </mark> (Gran & Paola, 2001).</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-3069-041201041229.jpg" alt="Figure 3: Dalton's ball and hook model for the atom." /> </button> <figcaption> <p><strong>Figure 3:</strong> Dalton's ball and hook model for the atom.</p> </figcaption> </figure> </div> <p><mark id="ngss-89" class="ngss"> Once a <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> is built (either in concept, physical space, or in a computer), it can be tested using a given set of conditions. The results of these tests can then be compared against reality in order to <mark class="term" data-term="validate" data-term-def="To establish the soundness or truth of something, often using an independent means of checking results. Validation of data, models, statistical&hellip;" data-term-url="/en/glossary/view/validate/3901">validate</mark> the model. In other words, how well does the model do at matching what we see in the real world? In the physical model of <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark> <mark class="term" data-term="sediment" data-term-def="Loose, unconsolidated material of the following compositions: <br> 1. rock fragments (also called clasts) transported by wind, moving water,&hellip;" data-term-url="/en/glossary/view/sediment/3310">sediments</mark>, the scientists who built the model looked for features like the layering of sand that they have seen in the real world. If the model shows something really different than what the scientists expect, the relationships between <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> may need to be redefined or the scientists may have oversimplified the <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark>. Then the model is revised, improved, tested again, and compared to <mark class="term" data-term="observation" data-term-def="1. The act of noticing something. 2. A record of that which has been noticed." data-term-url="/en/glossary/view/observation/8255">observations</mark> again in an ongoing, <mark class="term" data-term="iterative" data-term-def="Repetitive in a cyclical fashion. An iterative process or method in science is one in which a sequence of steps is&hellip;" data-term-url="/en/glossary/view/iterative/3847">iterative</mark> <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark>.</mark> For example, the conceptual "billiard ball" model of the <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atom</mark> used in the early 1800s worked for some aspects of the behavior of gases, but when that <mark class="term" data-term="hypothesis" data-term-def="From the Greek word <em>hypothesis</em> meaning assumption or the basis of an argument, a hypothesis is a proposal intended to explain&hellip;" data-term-url="/en/glossary/view/hypothesis/3727">hypothesis</mark> was tested for <mark class="term" data-term="chemical reaction" data-term-def="A process in which atoms and molecules recombine by forming or breaking chemical bonds. Chemical reactions form new products that&hellip;" data-term-url="/en/glossary/view/chemical+reaction/1547">chemical reactions</mark>, it didn't do a good job of explaining how they occur – billiard balls do not normally interact with one another. <mark class="term" data-term="John Dalton" data-term-def="English physicist, chemist and meteorologist born in Eaglesfield, Cumberland (1766-1844). Dalton published <i>Experimental Essays on the Constitution of Mixed Gases; on&hellip;" data-term-url="/en/glossary/view/Dalton%2C+John/4518">John Dalton</mark> envisioned a revision of the model in which he added "hooks" to the billiard ball model to account for the fact that atoms could join together in <mark class="term" data-term="reaction" data-term-def="A chemical change when substances come into contact with each other." data-term-url="/en/glossary/view/reaction/8263">reactions</mark>, as conceptualized in Figure 3.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form name="cc5865"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">Once a model is built, it is never changed or modified.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-5865-0-option-a" name="quiz-option-5865" type="radio" value="True." > <span class="option__label"> <span class="screen-reader-only">a.</span> True. </span> </label> <span class="quiz__response" id="response-5865-0"> <strong>Incorrect.</strong> </span> </div> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-5865-1-option-b" name="quiz-option-5865" type="radio" value="False." > <span class="option__label"> <span class="screen-reader-only">b.</span> False. </span> </label> <span class="quiz__response" id="response-5865-1"> <strong>Correct!</strong> </span> </div> </div> </div> </div> </form> </div> <p>While conceptual and physical <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> have long been a component of all scientific disciplines, computer-based modeling is a more recent development, and one that is frequently misunderstood. Computer models are based on exactly the same <mark class="term" data-term="principle" data-term-def="In the sciences, a principle is a fundamental, primary, or general law or truth. For instance, one of the most basic&hellip;" data-term-url="/en/glossary/view/principle/5289">principles</mark> as conceptual and physical models, however, and they take advantage of relatively recent advances in computing power to mimic real <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">systems</mark>.</p></section> <section id="toc_3"> <h2>The beginning of computer modeling: Numerical weather prediction</h2><p><mark id="ngss-90" class="ngss"> In the late 19<sup>th</sup> century, <mark class="term" data-term="Vilhelm Bjerknes" data-term-def="Norwegian mathematician, physicist and meteorologist born in Christiana, Norway (now Oslo) (1862-1951). Bjerknes proposed the concept of numerical weather prediction, developed&hellip;" data-term-url="/en/glossary/view/Bjerknes%2C+Vilhelm/4455">Vilhelm Bjerknes</mark>, a Norwegian mathematician and physicist, became interested in deriving equations that govern the large-scale motion of air in the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark>. Importantly, he recognized that <mark class="term" data-term="circulation" data-term-def="Generally, movement within a system. 1. [Atmospheric] the movement of air masses within the troposphere, driven by the redistribution of energy&hellip;" data-term-url="/en/glossary/view/circulation/10355">circulation</mark> was the result not just of thermodynamic properties (like the tendency of hot air to rise), but of hydrodynamic properties as well, which describe the behavior of <mark class="term" data-term="fluid" data-term-def="Able to flow because the intermolecular forces allow the molecules to move around in relation to one another. Both liquids and&hellip;" data-term-url="/en/glossary/view/fluid/8724">fluid</mark> flow. Through his work, he developed an equation that described the physical processes involved in atmospheric circulation, which he published in 1897. The complexity of the equation reflected the complexity of the atmosphere, and Bjerknes was able to use it to describe why weather fronts develop and move.</mark></p></section> <section id="toc2_1"><h3>Using calculations predictively</h3><p>Bjerknes had another vision for his mathematical work, however: <mark id="ngss-91" class="ngss">He wanted to predict the weather. The goal of weather prediction, he realized, is not to know the paths of individual air <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> over time, but to provide the public with "average <mark class="term" data-term="value" data-term-def="A number that is assigned based on measurement or a calculation. In mathematics, an unknown value that is commonly represented by&hellip;" data-term-url="/en/glossary/view/value/8254">values</mark> over large areas and long <mark class="term" data-term="period" data-term-def="A row of elements in the periodic table." data-term-url="/en/glossary/view/period/8565">periods</mark> of time." Because his equation was based on physical <mark class="term" data-term="principle" data-term-def="In the sciences, a principle is a fundamental, primary, or general law or truth. For instance, one of the most basic&hellip;" data-term-url="/en/glossary/view/principle/5289">principles</mark>, he saw that by entering the present values of atmospheric <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> like air pressure and temperature, he could solve it to predict the air pressure and temperature at some time in the future. In 1904, Bjerknes published a short paper describing what he called "the principle of predictive meteorology",</mark> (Bjerknes, 1904) (see the Research links for the entire paper). In it, he says:</p><blockquote class="blockquote"> <p>Based upon the observations that have been made, the initial state of the atmosphere is represented by a number of charts which give the distribution of seven variables from level to level in the atmosphere. With these charts as the starting point, new charts of a similar kind are to be drawn, which represent the new state from hour to hour. </p> </p></blockquote><p>In other words, Bjerknes envisioned drawing a series of weather charts for the future based on using known quantities and physical <mark class="term" data-term="principle" data-term-def="In the sciences, a principle is a fundamental, primary, or general law or truth. For instance, one of the most basic&hellip;" data-term-url="/en/glossary/view/principle/5289">principles</mark>. He proposed that solving the complex equation could be made more manageable by breaking it down into a series of smaller, sequential calculations, where the results of one calculation are used as input for the next. As a simple example, imagine predicting traffic patterns in your neighborhood. You start by drawing a map of your neighborhood showing the location, speed, and direction of every car within a square mile. Using these <mark class="term" data-term="parameter" data-term-def="In statistics, a parameter is a numerical value that represents a characteristic of a statistical population. Contrast with statistic." data-term-url="/en/glossary/view/parameter/9481">parameters</mark>, you then calculate where all of those cars are one minute later. Then again after a second minute. Your calculations will likely look pretty good after the first minute. After the second, third, and fourth minutes, however, they begin to become less accurate. Other factors you had not included in your calculations begin to exert an influence, like where the person driving the car wants to go, the right- or left-hand turns that they make, delays at traffic <mark class="term" data-term="light" data-term-def="A form of electromagnetic radiation. Visible light is that associated with stimulating the organs of sight, which for normal human&hellip;" data-term-url="/en/glossary/view/light/1498">lights</mark> and stop signs, and how many new drivers have entered the roads. </p><p>Trying to include all of this information simultaneously would be mathematically difficult, so, as proposed by Bjerknes, the problem can be solved with sequential calculations. To do this, you would take the first step as described above: Use location, speed, and direction to calculate where all the cars are after one minute. Next, you would use the information on right- and left-hand turn <mark class="term" data-term="frequency" data-term-def="The rate at which a vibration occurs that constitutes a wave, either in a material or in an electromagnetic field, usually&hellip;" data-term-url="/en/glossary/view/frequency/2210">frequency</mark> to calculate changes in direction, and then you would use information on traffic <mark class="term" data-term="light" data-term-def="A form of electromagnetic radiation. Visible light is that associated with stimulating the organs of sight, which for normal human&hellip;" data-term-url="/en/glossary/view/light/1498">light</mark> delays and new traffic to calculate changes in speed. After these three steps are done, you would solve your first equation again for the second minute time sequence, using location, speed, and direction to calculate where the cars are after the second minute. Though it would certainly be rather tiresome to do by hand, this series of sequential calculations would provide a manageable way to estimate traffic patterns over time.</p> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="3321739899"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> <p><mark id="ngss-92" class="ngss">Although this <mark class="term" data-term="method" data-term-def="A procedure or process; a systematic way of performing a task or conducting research." data-term-url="/en/glossary/view/method/8238">method</mark> made calculations tedious, Bjerknes imagined "no intractable mathematical difficulties" with predicting the weather. The method he proposed (but never used himself) became known as numerical weather prediction, and it represents one of the first approaches towards numerical modeling of a complex, dynamic <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark>.</mark></p></section> <section id="toc2_2"><h3>Advancing weather calculations</h3><p>Bjerknes' challenge for numerical weather prediction was taken up sixteen years later in 1922 by the English scientist <mark class="term" data-term="Lewis Fry Richardson" data-term-def="English meteorologist born in Newcastle upon Tyne, Northumberland (1881-1953). Richardson was the first to apply mathematics (the method of finite differences)&hellip;" data-term-url="/en/glossary/view/Richardson%2C+Lewis+Fry/4567">Lewis Fry Richardson</mark>. <mark id="ngss-93" class="ngss">Richardson related seven <mark class="term" data-term="differential equation" data-term-def="An equation relating a variable that changes over time (referred to as a <i>function</i>), to its rate of change (referred to&hellip;" data-term-url="/en/glossary/view/differential+equation/3902">differential equations</mark> that built on Bjerknes' atmospheric <mark class="term" data-term="circulation" data-term-def="Generally, movement within a system. 1. [Atmospheric] the movement of air masses within the troposphere, driven by the redistribution of energy&hellip;" data-term-url="/en/glossary/view/circulation/10355">circulation</mark> equation to include additional atmospheric processes. One of Richardson's great contributions to <mark class="term" data-term="mathematical modeling" data-term-def="The process of analyzing and describing real-life situations using appropriate mathematics and statistics. Modeling is often used to express a&hellip;" data-term-url="/en/glossary/view/mathematical+modeling/10799">mathematical modeling</mark> was to solve the equations for boxes within a grid; he divided the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark> over Germany into 25 squares that corresponded with available weather station <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark> (see Figure 4) and then divided the atmosphere into five layers, creating a three-dimensional grid of 125 boxes. This was the first use of a technique that is now standard in many types of modeling. For each box, he calculated each of nine <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> in seven equations for a single time step of three hours. This was not a simple sequential calculation, however, since the <mark class="term" data-term="value" data-term-def="A number that is assigned based on measurement or a calculation. In mathematics, an unknown value that is commonly represented by&hellip;" data-term-url="/en/glossary/view/value/8254">values</mark> in each box depended on the values in the adjacent boxes, in part because the air in each box does not simply stay there – it moves from box to box.</mark></p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_4215.gif" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-4215-081113021111.jpg" alt="Figure 4: Data for Richardson's forecast included measurements of winds, barometric pressure and temperature. Initial data were recorded in 25 squares, each 200 kilometers on a side, but conditions were forecast only for the two central squares outlined in red. " /> </button> <figcaption> <p><strong>Figure 4:</strong> Data for Richardson's forecast included measurements of winds, barometric pressure and temperature. Initial data were recorded in 25 squares, each 200 kilometers on a side, but conditions were forecast only for the two central squares outlined in red. </p> <span class="credit">image ©Brian Hayes, American Scientist</span> </figcaption> </figure> </div> <p><mark id="ngss-94" class="ngss">Richardson's attempt to make a six-hour forecast took him nearly six weeks of work with pencil and paper and was considered an utter failure, as it resulted in calculated barometric pressures that exceeded any historically measured <mark class="term" data-term="value" data-term-def="A number that is assigned based on measurement or a calculation. In mathematics, an unknown value that is commonly represented by&hellip;" data-term-url="/en/glossary/view/value/8254">value</mark> (Dalmedico, 2001). Probably influenced by Bjerknes, Richardson attributed the failure to inaccurate input <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark>, whose errors were magnified through successive calculations</mark> (see more about error propagation in our <a href="/library/module_viewer.php?mid=157">Uncertainty, Error, and Confidence</a> module).</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_4216.jpg" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-4216-081113021118.jpg" alt="Figure 5: Norwegian stamp bearing an image of Vilhelm Bjerknes" /> </button> <figcaption> <p><strong>Figure 5:</strong> Norwegian stamp bearing an image of Vilhelm Bjerknes</p> </figcaption> </figure> </div> <p>In addition to his concerns about inaccurate input <mark class="term" data-term="parameter" data-term-def="In statistics, a parameter is a numerical value that represents a characteristic of a statistical population. Contrast with statistic." data-term-url="/en/glossary/view/parameter/9481">parameters</mark>, Richardson realized that weather prediction was limited in large part by the speed at which individuals could calculate by hand. He thus envisioned a "forecast factory," in which thousands of people would each complete one small part of the necessary calculations for rapid weather forecasting. </p></section> <section id="toc2_3"><h3>First computer for weather prediction</h3><p><mark id="ngss-95" class="ngss"> Richardson's vision became reality in a sense with the birth of the computer, which was able to do calculations far faster and with fewer errors than humans. The computer used for the first one-day weather prediction in 1950, nicknamed <mark class="term" data-term="ENIAC" data-term-def="Short for Electronic Numerical Integrator and Computer; the first general-purpose electronic computer. It was the first high-speed, digital computer capable of&hellip;" data-term-url="/en/glossary/view/ENIAC/3936">ENIAC</mark> (Electronic Numerical Integrator and Computer), was 8 feet tall, 3 feet wide, and 100 feet long – a behemoth by modern standards, but it was so much faster than Richardson's hand calculations that by 1955, meteorologists were using it to make forecasts twice a day (Weart, 2003). Over time, the <mark class="term" data-term="accuracy" data-term-def="In science, the term accuracy describes how well a measurement approximates the theoretically correct value of that measurement, for example, how&hellip;" data-term-url="/en/glossary/view/accuracy/4222">accuracy</mark> of the forecasts increased as better <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark> became available over the entire globe through <mark class="term" data-term="radar" data-term-def="a system for detecting the presence of objects, like raindrops, by sending out pulses of high-frequency electromagnetic waves that are reflected&hellip;" data-term-url="/en/glossary/view/radar/12931">radar</mark> technology and, eventually, satellites.</mark></p><p><mark id="ngss-101" class="ngss"> The <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark> of numerical weather prediction developed by Bjerknes and Richardson laid the foundation not only for modern <mark class="term" data-term="meteorology" data-term-def="The scientific study of the atmosphere including the processes that cause particular weather conditions." data-term-url="/en/glossary/view/meteorology/11227">meteorology</mark>, but for computer-based <mark class="term" data-term="mathematical modeling" data-term-def="The process of analyzing and describing real-life situations using appropriate mathematics and statistics. Modeling is often used to express a&hellip;" data-term-url="/en/glossary/view/mathematical+modeling/10799">mathematical modeling</mark> as we know it today.</mark> In fact, after Bjerknes died in 1951, the Norwegian government recognized the importance of his contributions to the science of meteorology by issuing a stamp bearing his portrait in 1962 (Figure 5).</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form name="cc5871"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">Weather prediction is based on _____________ modeling.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-5871-0-option-a" name="quiz-option-5871" type="radio" value="mathematical" > <span class="option__label"> <span class="screen-reader-only">a.</span> mathematical </span> </label> <span class="quiz__response" id="response-5871-0"> <strong>Correct!</strong> </span> </div> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-5871-1-option-b" name="quiz-option-5871" type="radio" value="physical" > <span class="option__label"> <span class="screen-reader-only">b.</span> physical </span> </label> <span class="quiz__response" id="response-5871-1"> <strong>Incorrect.</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_4"> <h2>Modeling in practice: The development of global climate models</h2><p><mark id="ngss-96" class="ngss">The desire to <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> Earth's <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> on a long-term, global scale grew naturally out of numerical weather prediction. The goal was to use equations to describe atmospheric <mark class="term" data-term="circulation" data-term-def="Generally, movement within a system. 1. [Atmospheric] the movement of air masses within the troposphere, driven by the redistribution of energy&hellip;" data-term-url="/en/glossary/view/circulation/10355">circulation</mark> in order to understand not just tomorrow's weather, but large-scale patterns in global climate, including dynamic features like the jet stream and major climatic shifts over time like ice ages.</mark> Initially, scientists were hindered in the development of valid models by three things: a lack of <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark> from the more inaccessible components of the <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark> like the upper <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark>, the sheer complexity of a system that involved so many interacting components, and limited computing powers. Unexpectedly, World War II helped solve one problem as the newly-developed technology of high altitude aircraft offered a window into the upper atmosphere (see our Technology module for more information on the development of aircraft). The jet stream, now a familiar feature of the weather broadcast on the news, was in fact first documented by American bombers flying westward to Japan.</p><p>As a result, global atmospheric <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> began to feel more within reach. <mark id="ngss-97" class="ngss"> In the early 1950s, Norman Phillips, a meteorologist at Princeton University, built a mathematical model of the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark> based on fundamental thermodynamic equations (Phillips, 1956). He defined 26 <mark class="term" data-term="variable" data-term-def="In math, an expression that can be assigned any set of values. Variables are written as symbols, such as x, y&hellip;" data-term-url="/en/glossary/view/variable/3797">variables</mark> related through 47 equations, which described things like <mark class="term" data-term="evaporation" data-term-def="a change in the state of matter from the liquid phase (water) into the gas phase (water vapor)." data-term-url="/en/glossary/view/evaporation/12928">evaporation</mark> from Earth's <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark>, the rotation of the Earth, and the change in air pressure with temperature. In the model, each of the 26 variables was calculated in each square of a 16 x 17 grid that represented a piece of the northern hemisphere. The grid represented an extremely simple <mark class="term" data-term="landscape" data-term-def="The natural scenery of a region; a collection of landforms in an area." data-term-url="/en/glossary/view/landscape/8559">landscape</mark> – it had no continents or oceans, no mountain ranges or topography at all. This was not because Phillips thought it was an accurate representation of reality, but because it simplified the calculations. He started his model with the atmosphere "at rest," with no predetermined air movement, and with yearly <mark class="term" data-term="average" data-term-def="In statistics, average commonly refers to the arithmetic mean, also called simply "mean," which is one measure of the mid-point of&hellip;" data-term-url="/en/glossary/view/average/8542">averages</mark> of input <mark class="term" data-term="parameter" data-term-def="In statistics, a parameter is a numerical value that represents a characteristic of a statistical population. Contrast with statistic." data-term-url="/en/glossary/view/parameter/9481">parameters</mark> like air temperature.</mark></p><p><mark id="ngss-98" class="ngss"> Phillips ran the <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">model</mark> through 26 simulated day-night cycles by using the same kind of sequential calculations Bjerknes proposed. Within only one "day," a pattern in atmospheric pressure developed that strongly resembled the typical weather <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">systems</mark> of the portion of the northern hemisphere he was modeling (see Figure 6). In other words, despite the simplicity of the model, Phillips was able to reproduce key features of atmospheric <mark class="term" data-term="circulation" data-term-def="Generally, movement within a system. 1. [Atmospheric] the movement of air masses within the troposphere, driven by the redistribution of energy&hellip;" data-term-url="/en/glossary/view/circulation/10355">circulation</mark>, showing that the topography of the Earth was not of primary importance in atmospheric circulation. His work laid the foundation for an entire subdiscipline within <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> science: development and refinement of <mark class="term" data-term="General Circulation Model" data-term-def="Also referred to as General Climate Models; a class of computer models used for weather forecasting and understanding or projecting climate&hellip;" data-term-url="/en/glossary/view/General+Circulation+Model/3926">General Circulation Models</mark> (GCMs).</mark></p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_4217.jpg" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-4217-081113021121.jpg" alt="Figure 6: A model result from Phillips' 1956 paper. The box in the lower right shows the size of a grid cell. The solid lines represent the elevation of the 1000 millibar pressure, so the H and L represent areas of high and low pressure, respectively. The dashed lines represent lines of constant temperature, indicating a decreasing temperature at higher latitudes. This is the 23rd simulated day." /> </button> <figcaption> <p><strong>Figure 6:</strong> A model result from Phillips' 1956 paper. The box in the lower right shows the size of a grid cell. The solid lines represent the elevation of the 1000 millibar pressure, so the H and L represent areas of high and low pressure, respectively. The dashed lines represent lines of constant temperature, indicating a decreasing temperature at higher latitudes. This is the 23<sup>rd</sup> simulated day.</p> </figcaption> </figure> </div> <p>By the 1980s, computing power had increased to the point where modelers could incorporate the distribution of oceans and continents into their <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark>. In 1991, the eruption of Mt. Pinatubo in the Philippines provided a natural experiment: How would the addition of a significant <mark class="term" data-term="volume" data-term-def="The amount of space taken up by matter, commonly expressed in cubic centimeters (cm<sup>3</sup>) or milliliters (ml)." data-term-url="/en/glossary/view/volume/8515">volume</mark> of sulfuric <mark class="term" data-term="acid" data-term-def="Generally, a substance that reacts with bases to form a salt, several different definitions of acids have been proposed by different&hellip;" data-term-url="/en/glossary/view/acid/1573">acid</mark>, carbon dioxide, and volcanic ash affect global climate? In the aftermath of the eruption, descriptive <mark class="term" data-term="method" data-term-def="A procedure or process; a systematic way of performing a task or conducting research." data-term-url="/en/glossary/view/method/8238">methods</mark> (see our <a href="/library/module_viewer.php?mid=151">Description in Scientific Research</a> module) were used to document its effect on global climate: Worldwide measurements of sulfuric acid and other components were taken, along with the usual air temperature measurements. Scientists could see that the large eruption had affected <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark>, and they quantified the extent to which it had done so. This provided a perfect test for the <mark class="term" data-term="GCM" data-term-def="See <a href="http://www.visionlearning.com/en/glossary/index/G#term-3926"> <br> General Circulation Model</a>." data-term-url="/en/glossary/view/GCM/4225">GCMs</mark>. Given the inputs from the eruption, could they accurately reproduce the effects that descriptive <mark class="term" data-term="research" data-term-def="A study or an investigation." data-term-url="/en/glossary/view/research/8257">research</mark> had shown? <mark id="ngss-99" class="ngss">Within a few years, scientists had demonstrated that GCMs could indeed reproduce the climatic effects induced by the eruption, and confidence in the abilities of GCMs to provide reasonable scenarios for future climate change grew. The validity of these models has been further substantiated by their ability to simulate past events, like ice ages, and the agreement of many different models on the range of possibilities for warming in the future,</mark> one of which is shown in Figure 7.</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox="image"> <img src="/img/library/modules/mid153/Image/VLObject-4245-081122071101.jpg" alt="Figure 7: Projected change in annual mean surface air temperature from the late 20th century (1971-2000 average) to the middle 21st century (2051-2060 average). Image courtesy NOAA Geophysical Fluid Dynamics Laboratory." /> </button> <figcaption> <p><strong>Figure 7:</strong> Projected change in annual mean surface air temperature from the late 20th century (1971-2000 average) to the middle 21st century (2051-2060 average). Image courtesy NOAA Geophysical Fluid Dynamics Laboratory.</p> </figcaption> </figure> </div> </section> <section id="toc_5"> <h2>Limitations and misconceptions of models</h2><p>The widespread use of modeling has also led to widespread misconceptions about <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark>, particularly with respect to their ability to predict. Some models are widely used for prediction, such as weather and streamflow forecasts, yet we know that weather forecasts are often wrong. Modeling still cannot predict exactly what will happen to the Earth's <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark>, but it can help us see the range of possibilities with a given set of changes. For example, many scientists have modeled what might happen to <mark class="term" data-term="average" data-term-def="In statistics, average commonly refers to the arithmetic mean, also called simply "mean," which is one measure of the mid-point of&hellip;" data-term-url="/en/glossary/view/average/8542">average</mark> global temperatures if the <mark class="term" data-term="concentration" data-term-def="The amount of one substance in relation to other components within a given area." data-term-url="/en/glossary/view/concentration/8733">concentration</mark> of carbon dioxide (CO<sub>2</sub>) in the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark> is doubled from pre-industrial levels (pre-1950); though individual models differ in exact output, they all fall in the range of an increase of 2-6° C (IPCC, 2007).</p><p><mark id="ngss-100" class="ngss"> All <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> are also limited by the availability of <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark> from the real <mark class="term" data-term="system" data-term-def="A group of interacting, interrelated or interdependent components that form a complex whole. The size of the system is defined for&hellip;" data-term-url="/en/glossary/view/system/3904">system</mark>. As the amount of data from a system increases, so will the <mark class="term" data-term="accuracy" data-term-def="In science, the term accuracy describes how well a measurement approximates the theoretically correct value of that measurement, for example, how&hellip;" data-term-url="/en/glossary/view/accuracy/4222">accuracy</mark> of the model. For <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> modeling, that is why scientists continue to gather data about climate in the geologic past and monitor things like ocean temperatures with satellites – all those data help define <mark class="term" data-term="parameter" data-term-def="In statistics, a parameter is a numerical value that represents a characteristic of a statistical population. Contrast with statistic." data-term-url="/en/glossary/view/parameter/9481">parameters</mark> within the model. The same is true of physical and conceptual models, too, well-illustrated by the <mark class="term" data-term="evolution" data-term-def="Change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift." data-term-url="/en/glossary/view/evolution/5284">evolution</mark> of our model of the <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atom</mark> as our knowledge about subatomic <mark class="term" data-term="particle" data-term-def="A tiny piece of matter." data-term-url="/en/glossary/view/particle/8259">particles</mark> increased.</mark></p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form name="cc5872"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">__________ can result in a flawed model.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-5872-0-option-a" name="quiz-option-5872" type="radio" value="Lack of data about a system" > <span class="option__label"> <span class="screen-reader-only">a.</span> Lack of data about a system </span> </label> <span class="quiz__response" id="response-5872-0"> <strong>Correct!</strong> </span> </div> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-5872-1-option-b" name="quiz-option-5872" type="radio" value="Too much data about a system" > <span class="option__label"> <span class="screen-reader-only">b.</span> Too much data about a system </span> </label> <span class="quiz__response" id="response-5872-1"> <strong>Incorrect.</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_6"> <h2>Modeling in modern practice</h2><p>The various types of modeling play important roles in virtually every scientific discipline, from ecology to analytical chemistry and from <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> dynamics to geology. Physical <mark class="term" data-term="model" data-term-def="A representation, pattern, or mathematical description that can help scientists replicate a system." data-term-url="/en/glossary/view/model/8236">models</mark> such as the river <mark class="term" data-term="delta" data-term-def="Deltas form where rivers reach lakes, seas, or the ocean, and deposit their remaining sediment in a broad, flat plain as&hellip;" data-term-url="/en/glossary/view/delta/3309">delta</mark> take advantage of cutting edge technology to integrate multiple large-scale processes. As computer processing speed and power have increased, so has the ability to run models on them. From the room-sized <mark class="term" data-term="ENIAC" data-term-def="Short for Electronic Numerical Integrator and Computer; the first general-purpose electronic computer. It was the first high-speed, digital computer capable of&hellip;" data-term-url="/en/glossary/view/ENIAC/3936">ENIAC</mark> in the 1950s to the closet-sized Cray <mark class="term" data-term="supercomputer" data-term-def="A very fast, powerful mainframe computer, used in advanced military and scientific applications." data-term-url="/en/glossary/view/supercomputer/4224">supercomputer</mark> in the 1980s to today's laptop, processing speed has increased over a million-fold, allowing scientists to run models on their own computers rather than booking time on one of only a few supercomputers in the world. Our conceptual models continue to evolve, and one of the more recent <mark class="term" data-term="theory" data-term-url="/en/glossary/view/theory" data-term-def="A scientific theory is an explanation inferred from multiple lines of evidence for some broad aspect of the natural world and&hellip;">theories</mark> in theoretical physics digs even deeper into the structure of the <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atom</mark> to propose that what we once thought were the most fundamental <mark class="term" data-term="particle" data-term-def="A tiny piece of matter." data-term-url="/en/glossary/view/particle/8259">particles</mark> – quarks – are in fact composed of vibrating filaments, or strings. String <mark class="term" data-term="theory" data-term-def="A scientific theory is an explanation inferred from multiple lines of evidence for some broad aspect of the natural world and&hellip;" data-term-url="/en/glossary/view/theory/4854">theory</mark> is a complex conceptual model that may help explain gravitational <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">force</mark> in a way that has not been done before. Modeling has also moved out of the realm of science into recreation, and many computer games like SimCity® involve both conceptual modeling (answering the question, "What would it be like to run a city?") and computer modeling, using the same kinds of equations that are used model traffic flow patterns in real cities. The accessibility of modeling as a <mark class="term" data-term="research" data-term-def="A study or an investigation." data-term-url="/en/glossary/view/research/8257">research</mark> <mark class="term" data-term="method" data-term-def="A procedure or process; a systematic way of performing a task or conducting research." data-term-url="/en/glossary/view/method/8238">method</mark> allows it to be easily combined with other scientific research methods, and scientists often incorporate modeling into experimental, descriptive, and <mark class="term" data-term="comparative" data-term-def="Identifying similarities and differences." data-term-url="/en/glossary/view/comparative/8240">comparative</mark> studies.</p></section> <footer class="module__main__footer"> <hr class="border-color-dark"> <p class="citation"> <em> Anne E. Egger, Ph.D., Anthony Carpi, Ph.D. “Modeling in Scientific Research” Visionlearning Vol. POS-1 (8), 2008. </em> </p>  <div class="title-list" id="refs" name="refs"> <p class="h6 title-list__title"> References </p> <ul class="title-list__list"> <li><p>Bjerknes, V. (1904). Das Problem der Wettervorhersage, betrachtet vom Standpunkte der Mechanik und der Physik. <em>Meteorologische Zeitschrift, 21,</em> 1-7.</li> <li>Dalmedico, A. D. (2001). History and epistemology of models: Meteorology (1946-1963) as a case study. <em>Archive for History of Exact Sciences, 55</em>(5), 395.</li> <li>Gran, K., & Paola, C. (2001). Riparian vegetation controls on braided stream dynamics. <em>Water Resources Research, 37</em>(12), 3275-3283.</li> <li>IPCC. (2007). <em>Climate change 2007: The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change</em>. New York: Cambridge University Press.</li> <li>Paola, C., Mullin, J., Ellis, C., Mohrig, D. C., Swenson, J. B., Parker, G., . . . Strong, N. (2001). Experimental stratigraphy. <em>GSA Today, 11</em>(7), 4-9.</li> <li>Phillips, N. A. (1956). The general circulation of the atmosphere: A numerical experiment. <em>Quarterly Journal of the Royal Meteorological Society, 82</em>(352), 123-164.</li> <li>Weart, S. (2003). <a href="http://www.aip.org/history/climate/">The discovery of global warming</a>. American Institute of Physics.</p></li> </ul> </div>  <div class="title-list" name="further"> <p class="h6 title-list__title"> Further Reading </p> <ul class="grid grid--column-2--md grid--column-3--md gap-1"> <li> <a class="no-hover-focus height-100" href="/en/library/Process-of-Science/49/Experimentation-in-Scientific-Research/150"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_150-23061210061411.jpeg" alt="Experimentation in Scientific Research"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Experimentation in Scientific Research: <em>Variables and controls in practice</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Process-of-Science/49/Description-in-Scientific-Research/151"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_151-23061210061423.jpeg" alt="Description in Scientific Research"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Description in Scientific Research: <em>Observations and multiple working hypotheses</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Process-of-Science/49/Comparison-in-Scientific-Research/152"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_152-23061210061436.jpeg" alt="Comparison in Scientific Research"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Comparison in Scientific Research: <em>Uncovering statistically significant relationships</em> </h2> </div> </article> </a> </li> </ul> </div> </footer> </div>    </article> </div> </div> </main> <script id="ngssCommentdata" type="application/json"> [{"ngss_tag_id":null,"type":"cc","tag":null,"name":null,"description":null,"comment":"Engineers and geologists built a model of the Mississippi River delta to better understand and predict the processes involved in sediment transport in the river system. 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