国外心理学研究方法课件19.nonexp1

Non-Experimentaldesigns:SurveysPsych231:ResearchMethodsinPsychologyNon-ExperimentaldesignsSometimesyoujustcan’tperformafullycontrolledexperimentBecauseoftheissueofinterestLimitedresources(notenoughsubjects,observationsaretoocostly,etc.).Thereareotherkindsofdesignsthatmaybeused•Surveys•Correlationalstudies•Quasi-Experiments•Developmentaldesigns•Small-NdesignsThisdoesNOTimplythattheyarebaddesignsJustremembertheadvantagesanddisadvantagesofeachSurveysWhatarethey?QuestionnairesandinterviewsthataskpeopletoprovideinformationaboutthemselvesWhyconductthem?Bestwaytocollectsomekindsofinformation:•Descriptive,behavioral,andpreferential•e.g.,demographicinformation,recreationalbehavior,andattitudesTocomplimentexperimentalwork•Good/commonfirststep,cancollectalotofdataaboutalotofvariables•DonothavetodirectlyobservebehaviorsPewResearchCenterSurveysAdvantagesOnecaninvestigateinternalevents•e.g.,attitudes&opinionsCangeneralizeaboutanentirepopulationbasedonrelativelysmallsamplesofindividualsLargeamountsofdatacanbecollectedquicklywithrelativelylittlecost(effort,time,etc.)•Butthey’reoftennotas“cheap”asyoumaythinkSurveysDisadvantagesCorrelational:causalclaimsshouldn’tbemade•Oftenusedfordescriptiveandpredictiveresearchquestions•Note:surveysaresometimesusedaspartofanexperimentaldesign,whichmayallowtestingofcausalclaimsNon-responsebias•Whydoesn’teverybodyrespond?•Doesresponserateinteractwithvariablesofinterest?Self-reportsmaynotbetruthful•Responseset-tendencytorespondfromaparticularperspective•Socialdesirabilitybias(e.g.,howa“moral”personwouldanswer)Largedatasetsaresometimesdifficulttoanalyze10StagesofsurveyresearchStage1)IdentifythefocusofthestudyandselectyourresearchmethodWhataretheobjectivesoftheresearch?Isasurveymethodthebestapproach?Whatkindofsurveyshouldbeused?•Groupadministration•Mailsurveys•Internetsurveys•Telephonesurveys•Face-to-faceinterviews•Focusgroupinterviews10StagesofsurveyresearchStage2)DeterminingtheresearchscheduleandbudgetStage3)EstablishinganinformationbaseFindoutwhat’sbeendone,what’sknown•E.g.,FindotherrelatedsurveysStage4)IdentifythesamplingframeTheactualpopulationthatthesampleisdrawnfrom(asopposedtotheidealpopulation)•Thinkofitasoperationalizingtheconceptuallevelpopulation•Beawareofpotentialcoverageerror–whenthesamplingdoesn’tleadtoagoodrepresentativeness10StagesofsurveyresearchStage5)DeterminingthesamplemethodandsamplingsizeReviewProbabilityandNon-Probabilitymethods•VoluntaryresponsemethodImportanceofsamplesizeVoluntaryresponsemethodsAkindofconveniencesamplingmethodscommonlyused•Problem:Typicallyonlyindividualswithstrongopinionsrespond,sotheresultsareoftenextremelybiasedShouldleftoverHalloweencandybegivenouttostudentswhogetanAontheexam?Call123-NONOifyouthinkNOCall123-4YESifyouthinkYESDailyshowclipAnotherfunpollresultImportanceofsamplesizeSamplingerror-howisthesampledifferentfromthepopulation?Confidenceintervals•Anestimateofthemeanorpercentageofthepopulation,basedonthesampledata•“JohnDoehas55%ofthevote,withamarginoferror±3%”•Marginoferror(that“±3%”part)•Thelargeryoursamplesize,thesmalleryourmarginoferrorwillbe.•Whichwouldyoubemorelikelytobelieve•“Weasked10people…”•“Weasked1000people…”ImportanceofsamplesizeSamplingerror-howisthesampledifferentfromthepopulation?Responserate•Whatproportionofthesampleactuallyrespondedtothesurvey?•Hiddencostshere-whatcanyoudotoincreaseresponserates•Non-responseerror(bias)•Istheresomethingspecialaboutthedatathatyou’remissing(Fromthepeoplewhodidn’trespond)?10StagesofsurveyresearchStage6)DesigningthesurveyinstrumentQuestionconstruction:Howthequestionsarewrittenisveryimportant•Clearlyidentifytheresearchobjectives•Doyourquestionsreallytargetthoseresearchobjectives(thinkInternalandExternalValidity)?•Takecarewordingofthequestions•Keepitsimple,don’tasktwothingsatonce,avoidloadedorbiasedquestions,etc.•Howshouldquestionsbeanswered(questiontype)?GoodandpoorquestionsGoodPoorWastheFDCnegligentbyignoringthewarningsaboutVioxxduringtestingandapprovingitforsale?a)Yesb)Noc)UnsureDoyoufavoreliminatingthewastefulexcessinthepublicschoolbudget?a)Yesb)Noc)UnsureIftheFDCknewthatVioxxcausedserioussideeffectsduringtesting,whatshouldithavedone?a)Banitfromeverbeingsoldb)Requiremoretestingbeforeapprovingitc)UnsureDoyoufavorreducingthepublicschoolbudget?a)Yesb)Noc)UnsureProblem:emotionallychargedwordsGoodandpoorquestionsGoodPoorShouldseniorcitizensbegivenmoremoneyforrecreationcentersandfoodassistanceprograms?a)Yesb)Noc)UnsureShouldseniorcitizensbegivenmoremoneyforrecreationcenters?a)Yesb)Noc)UnsureShouldseniorcitizensbegivenmoremoneyforfoodassistanceprograms?a)Yesb)Noc)UnsureProblem:askstwodifferentquestionsGoodandpoorquestionsGoodPoorAreyouagainstsamesexmarriageandinfavorofaconstitutionalamendmenttobanit?a)Yesb)Noc)UnsureWhatisyourviewonsamesexmarriage?a)Ithinkmarriageisamatterofpersonalchoiceb)I’magainstitbutdon’twantaconstitutionalamendmentc)IwantaconstitutionalamendmentbanningitProblem:BiasedinmorethanonedirectionProblem:AskstwoquestionsSurveyQuestionsQuestiontypesO