Scientific Method and Scientific Method and TheoryTheory

Dr. James Danoff-BurgDr. James Danoff-Burg

Columbia UniversityColumbia University

Goals of scienceGoals of science

Describe the patterns that are Describe the patterns that are found in the natural worldfound in the natural world

Explain patternsExplain patterns• This is the major emphasis of your This is the major emphasis of your

individual projectindividual project• Ditto for most of the activities that we Ditto for most of the activities that we

are doing in the classare doing in the class Scientific method is applicable to Scientific method is applicable to

many other aspects of lifemany other aspects of life

Methods of ExplanationMethods of Explanation

Approximately 11 StepsApproximately 11 Steps Process is repeated many timesProcess is repeated many times Can NEVER prove a hypothesisCan NEVER prove a hypothesis

• Can only reject many, leaving one as Can only reject many, leaving one as best supported by the databest supported by the data

• ““Scientific Proof” is a common fallacyScientific Proof” is a common fallacy

HypothesesHypotheses

Null hypothesisNull hypothesis• The hypothesis of no changeThe hypothesis of no change• Often abbreviated as HOften abbreviated as Hoo

Alternative hypotheses Alternative hypotheses • Often abbreviated as HOften abbreviated as Haa, H, Hbb, etc., etc.• All must be mutually exclusiveAll must be mutually exclusive• We accept one if HWe accept one if Hoo is statistically rejected is statistically rejected

– Which HWhich Haa to accept is determined by trends in to accept is determined by trends in datadata

Scientific Method - Steps Scientific Method - Steps 1-51-5

OObserve or suspect pattern bserve or suspect pattern PPosit significance of observed osit significance of observed

difference difference CCreate question to explain pattern reate question to explain pattern CCreate testable hypothesesreate testable hypotheses DDesign experiment esign experiment

Collect data (Descriptive stage) Collect data (Descriptive stage) Analyze data, primarily using Analyze data, primarily using

statistics statistics Evaluate hypotheses, reject HEvaluate hypotheses, reject Hoo? ? Make conclusions based on data Make conclusions based on data Note problems in current workNote problems in current work Predict future directions for researchPredict future directions for research

Scientific Method - Steps Scientific Method - Steps 6-116-11

Parts of a scientific reportParts of a scientific report

Title Title Abstract - an overall summary Abstract - an overall summary Introduction - background, question, HIntroduction - background, question, Haass Methods - what we didMethods - what we did Results - what we found, graphs, Results - what we found, graphs,

summarized datasummarized data Discussion - interpretations, predictions Discussion - interpretations, predictions Acknowledgements - who helped us Acknowledgements - who helped us References - who we citedReferences - who we cited

Scientific Communication Scientific Communication Written report Written report

• Traditional Traditional Oral presentation Oral presentation

• Commonly used for preliminary presentation of Commonly used for preliminary presentation of work to get feedback before writing it upwork to get feedback before writing it up

Poster Poster • Visual summary of work - used at conferencesVisual summary of work - used at conferences

Web page Web page • Can use a written report & make it interactiveCan use a written report & make it interactive

Individual Projects – Individual Projects – Seven Parts to DesignSeven Parts to Design

QuestionQuestion Null hypothesis & Alternative Null hypothesis & Alternative

hypotheseshypotheses Independent variable(s)Independent variable(s) Dependent variablesDependent variables Desired data to collectDesired data to collect Data collection methodData collection method Expected outcome with reasons as Expected outcome with reasons as

to why you expect thatto why you expect that