2023學(xué)年完整公開(kāi)課版Lecture2ResearchMethods

Lecture2:

ResearchMethods

Shun-nanYang,PhDDirectorofResearch,VisionPerformanceInstitute,CollegeofOptometry,PacificUniversityGoalsofPsychologyDescribeExplainPredictControlperceptual,mentalandbehavioralprocesses…ScientificSkepticismSciencehelpsbuildexplanationsthatareconsistentandpredictiveratherthanconflictingandpost-dictive(hindsight)ScienceisbasedonknowledgeoffactsdevelopingtheoriestestinghypothesespublicandrepeatableproceduresScientificMethodFormulatetestablequestionsDevelophypothesesDesignstudytocollectdataExperimentalDescriptiveAnalyzedatatoarriveatconclusionsUseofstatisticalproceduresUseofmeta-analysisReportresultsPublicationReplicationTheoryTentativeexplanationforobservedfindingsResultsfromaccumulationoffindingsofindividualstudiesToolforexplainingobservedbehaviorReflectsself-correctingnatureofscientificmethod.ResearchStrategiesDescriptive—strategiesforobservinganddescribingbehaviorNaturalisticobservationCasestudiesSurveysCorrelationalmethodsExperimental—strategiesforinferringcauseandeffectrelationshipsamongvariablesDescriptiveStudyDescribesasetoffactsDoesnotlookforrelationshipsbetweenfactsDoesnotpredictwhatmayinfluencethefactsMayormaynotincludenumericaldataExample:measurethepercentageofnewstudentsfromout-of-stateeachyearsince1980NaturalisticObservationResearchersdirectlyobserveandrecordbehaviorratherthanrelyingonsubjectdescriptions.In

naturalisticobservationresearcherrecordsbehaviorasitoccursnaturally.Example:ObservingstylesofClassroommanagement.CaseStudyMethodHighlydetaileddescriptionofasingleindividualGenerallyusedtoinvestigaterare,unusual,orextremeconditionsExample:Howadyslexicstudentcopeswithlearningdisabilitiesinschool.SurveyMethodsDesignedtoinvestigateopinions,behaviors,orcharacteristicsofaparticulargroup.Usuallyinself-reportform.SamplesandSamplingPopulation—large(potentiallyinfinite)grouprepresentedbythesample.Findingsaregeneralizedtothisgroup.Sample—selectedsegmentofthepopulationRepresentativesample—closelyparallelsthepopulationonrelevantcharacteristicsRandomassignment—everymemberoflargergrouphasequalchangeofbeingselectedforthestudysampleCorrelationalStudyCollectsasetoffactsorganizedintotwoormorecategoriesmeasuretimespentplayingvideogamesmeasureotherpersonalitycharacteristicsExaminestherelationshipbetweencategoriesCorrelationrevealsrelationshipsamongfactsCoefficientofCorrelationNumericalindicationofmagnitudeanddirectionoftherelationshipbetweentwovariablesPositivecorrelation—twovariablesvarysystematicallyintheSAMEdirectionNegativecorrelation—twovariablesvarysystematicallyinOPPOSITEdirectionsCorrelationalStudy CorrelationcannotprovecausationDoesplayingvideogamescauseadeclineinacademicachievement?Doesplayingvideogamescausemoreaggressivebehavior?Maybeanunmeasuredcommonfactore.g.,maybemoreaggressivepeopleareattractedtovideogames.ExperimentsDirectwaytotestahypothesisaboutacause-effectrelationshipbetweenfactorsFactorsarecalledvariablesOnevariableiscontrolledbytheexperimentere.g.,typeofvideogame--violentvs.non-violentTheotherisobservedandmeasurede.g.,aggressivebehaviorDefinitionsHypothesis—tentativestatementabouttherelationshipbetweenvariablesVariables—factorsthatcanvaryinwaysthatcanbeobserved,measured,andverifiedOperationaldefinition—precisedescriptionofhowthevariableswillbemeasuredExperimentalVariablesIndependentvariable(IV)thecontrolledfactorinanexperimenthypothesizedtocauseaneffectonanothervariableDependentvariable(DV)themeasuredfactshypothesizedtobeaffectedIndependentVariableMusthaveatleasttwolevelscategories–malevs.femalenumeric–ages10,12,14Simplestisexperimentalvs.controlgroupexperimentalgetstreatmentcontroldoesnotExperimentalDesignRandomsample—everymemberofthepopulationbeingstudiedshouldhaveanequalchanceofbeingselectedforthestudyRandomassignment—everysubjectinthestudyshouldhaveanequalchanceofbeingplacedineithertheexperimentalorcontrolgroupRandomizationhelpsavoidfalseresultsVariationsinDesignPlacebocontrolgroup—exposedtoafakeIV(placebo),theeffectsofwhicharecomparedtogroupreceivingtheactualIV.Double-blindstudy—techniqueinwhichneitherexperimenternorparticipantisawareofthegrouptowhichparticipantisassignedPossibleBiasExpectancyeffects—changeinDVproducedbysubject’sexpectancythatchangeshouldhappenDemandcharacteristics—subtlecuesorsignalsbytheresearcherthatcommunicatetypeofresponsesthatareexpected.BothcontrolledthroughuseofdoubleblindproceduresNaturalExperimentsOftenusedtomeasureimpactofnaturallyoccurringeventsUsedwhenactualexperimentsareimpossibleorunethicaltocreateExample:EffectsofchronicnoiseonstressinchildrenLimitationsOftencriticizedforhavinglittletodowithactualbehaviorbecauseofstrictlaboratoryconditionsEthicalconsiderationsincreatingsomemore“reallife”situationsEthicalGuidelinesInformedconsentandvoluntaryparticipationStudentsasparticipantsUseofdeceptionConfidentialityofrecordsInformationabout