Basics of Scientific InquiryCommon sense claimsThree lessons from MilgramWhat Is Scientific Inquiry?Slide 5Slide 6FalsifiabilityThe Bottom LineFalsifiable or Unfalsifiable?Slide 10The Nature of ScienceOckham's RazorThe Empirical ProcessBuilding a Psychological ScienceThe Methods of Psychological ScienceAn Experiment Involves Manipulating ConditionsTypes of ReasoningDeductive ResearchInductive ResearchInductive or Deductive?The ExperimentIndependent Variables are Manipulated by ExperimentersDependent Variables are Measured in Relation to IVsIdentify the IV and DVAn Experiment Involves Manipulating ConditionsList of Core Features of Experimental Methods:Operational DefinitionClass ActivityJames RandiBasics of Scientific InquiryBasics of Scientific InquiryCommon sense claimsCommon sense claimsCommon sense claims are often hunches based on anecdotal Common sense claims are often hunches based on anecdotal evidence: e.g. most people would not hurt another human evidence: e.g. most people would not hurt another human being just because an authority figure told them too. being just because an authority figure told them too. –Milgram’s (1966) famous experiment into conformity.Milgram’s (1966) famous experiment into conformity.–Approx 70% of those tested gave ‘electric shocks’ to Approx 70% of those tested gave ‘electric shocks’ to what they believed was another test subject, at a level what they believed was another test subject, at a level high enough to kill them. high enough to kill them. –Before carrying out the research, Milgram had asked Before carrying out the research, Milgram had asked other psychologists whether he should go ahead with the other psychologists whether he should go ahead with the experiment. He was told that nearly all participants experiment. He was told that nearly all participants would withdraw before causing any ‘pain.’would withdraw before causing any ‘pain.’ThreeThree lessons from Milgramlessons from Milgram•Skepticism is valuable.Skepticism is valuable.•Careful observation under controlled Careful observation under controlled conditions is very important.conditions is very important.•Observer expectancy results are real and Observer expectancy results are real and are research cancer. are research cancer. –Clever Hans wasn’t so clever, after all.Clever Hans wasn’t so clever, after all.What Is Scientific Inquiry?What Is Scientific Inquiry?Four goals of scientific inquiry:Four goals of scientific inquiry:•Description (Description (whatwhat happens) happens)•Prediction (Prediction (whenwhen it happens) it happens)•Causal control (Causal control (what causeswhat causes it to happen) it to happen)•Explanation (Explanation (whywhy it happens) it happens)How would we apply these goals to the study How would we apply these goals to the study of the effects of alcohol intoxication?of the effects of alcohol intoxication?An open mind and good An open mind and good imagination are not imagination are not enough. Research in the enough. Research in the psychological sciences psychological sciences requires a skeptical requires a skeptical attitude and objective attitude and objective methodologymethodology..FalsifiabilityFalsifiability•The case of blood-lettingThe case of blood-letting•For a theory to be useful, the predictions For a theory to be useful, the predictions drawn from it must be specific.drawn from it must be specific.– Tell us what will happenTell us what will happen– Tell us what will not happen Tell us what will not happen – How would we test for my ability to How would we test for my ability to mind read?mind read?The Bottom LineThe Bottom Line•Progress occurs in science when a Progress occurs in science when a theory does not predict theory does not predict everythingeverything..•Rather, science benefits from specific Rather, science benefits from specific predictions about phenomena, made predictions about phenomena, made in advance.in advance.•Falsifiability is liberating – making Falsifiability is liberating – making mistakes furthers progressmistakes furthers progressFalsifiable or Unfalsifiable?Falsifiable or Unfalsifiable?•Pepsi tastes better than Coca ColaPepsi tastes better than Coca Cola•Psychics can speak to the deadPsychics can speak to the dead•Aliens abduct us, do medical experiments on us Aliens abduct us, do medical experiments on us and then return us, leaving no evidenceand then return us, leaving no evidence•A theory with the empirical “trappings” of real science, including a system of theoretical concepts and a wealth of corroborating evidence.•But a pseudo-science has built-in “defense mechanisms” against possible refutation.•The Freudian theory provides an interpretation for every conceivable symptom of the patient.•Its “predictions” therefore can never be refuted.• http://www.youtube.com/watch?v=IWE5N8z2Aa4PseudosciencePseudoscienceThe Nature of ScienceThe Nature of Science–OrderOrder: there are regular patterns in events: there are regular patterns in events–DeterminismDeterminism: events have identifiable : events have identifiable causescauses–EmpiricismEmpiricism: theories should be based on : theories should be based on publicly available evidence gathered publicly available evidence gathered through objective observationthrough objective observation–ParsimonyParsimony: explanations should explain as : explanations should explain as much as possible as simply as possiblemuch as possible as simply as possibleA rule in science and philosophy stating that entities should not be multiplied needlessly. This rule is interpreted to mean that the simplest of two or more competing theories is preferable and that an explanation for unknown phenomena should first be attempted in terms of what is already known. Also called law of parsimony. Ockham's RazorOckham's RazorThe Empirical ProcessThe Empirical ProcessBuilding a Psychological ScienceBuilding a Psychological Science•Facts: Facts: –objective statement, based on direct observation, objective statement, based on direct observation, reasonable people agree withreasonable people agree with•Theories:Theories:–Interrelated set of concepts designed to explain Interrelated set of concepts designed to explain existing facts & generate new predictionsexisting facts & generate new predictions•Hypotheses & Specific Predictions:Hypotheses & Specific Predictions:–Predictions
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