Chapter-8-Experiments-欢迎光临-国立台北大学

PartThreeModesofObservationChapter8ExperimentsChapterOutlineIntroductionTopicsAppropriatetoExperimentsTheClassicalExperimentSelectingSubjectsIntroduction實驗？生活中其實充滿了實驗性交女朋？上課？翹課？煮飯？買手機……ChapterOutlineTopicsAppropriatefoExperimentsTheClassicalExperimentSelectingSubjectsVariationsonExperimentalDesignsAnIllustrationofExperimentationAlternateExperimentalSettingsStrengthsandWeaknessesoftheExperimentalMethod甚麼課題適合使用實驗法？Projectswithlimitedandwell-definedconcepts.概念範圍小而且明確：中文教材、英文教材

學生成績Projectsthatareexploratoryratherthandescriptive.解釋性(因果關係)而非描述性Studiesofsmallgroupinteraction.(小團體研究)：賦予不同的工作、給予不同的獎勵

團體的動態會有何不同？TheClassicalExperimentThreePairsIndependentanddependentvariablesPretestingandposttestingExperimentalandcontrolgroups1、自變項與依變項假設種族偏見源自於缺乏知識，因此接觸他族的資訊(自變項)愈豐富

偏見(依變項)會愈低自變項如何操作？依變項如何測量？特定而標準化的測量和觀察。QuestionInthesimplestexperimentaldesign,subjectsaremeasuredintermsofa_________variableexposedtoan_________variable.pretested;posttestedfluid;staticindependent;dependentdependent;independent2最簡單的實驗法：前測與後測前測：接收資料之前，測量個體的種族偏見程度(依變項)閱讀資料、觀看影片……(增多資訊之接受)後測，再測量種族偏見的程度(依變項)後測–前測：源自於自變項之改變Answer:DInthesimplestexperimentaldesign,subjectsaremeasuredintermsofadependentvariableexposedtoanindependentvariable.效度？如果受試者”感受”到：實驗是在檢視她/他的種族偏見程度，因此……。後測-前測：真是因為”接收了資訊”嗎？實驗過程的本身，而不是自變項的改變，可能就會造成受試者的改變兩個例子霍桑效果工廠的燈光亮度

工人的工作效果新葯有沒有效？新葯有沒有效？如果有兩組人，一組給新葯；另一組給糖漿，是否也都使病情改善？3、ExperimentalandControlGroups實驗組之外，另增控制組Experimentalgroup-Agroupofsubjectstowhomanexperimentalstimulusisadministered.Controlgroup-Agroupofsubjectstowhomnoexperimentalstimulusisadministeredandwhoresembletheexperimentalgroupinallotherrespects.僅實驗組接受實驗，即自變項的改變但，如果兩組人本來就不一樣？這兩組的成員Mustbeassimilaraspossible.控制組代表：如果實驗組沒有接受實驗，依變項會如何？Controlgrouprepresentswhattheexperimentalgroupwouldhavebeenlikehaditnotbeenexposedtothestimulus.Question

_____________groupsaregroupsofsubjectstowhomanexperimentalstimulusisadministered.controlexperimentalpurposivetriadAnswer:BExperimentalgroupsaregroupsofsubjectstowhomanexperimentalstimulusisadministered.DiagramofBasicExperimentalDesign如果再有其他事件發生種族偏見實驗的前、後測之間，發生了種族之間的剧烈衝突事件……上述的圖表所列，可不可以排除這個事件的影響？Double-blindExperiment在新葯的例子，施測者本身可能也會預期葯效，而誤判效果真的發生，因此…Anexperimentaldesigninwhichneitherthesubjectsnortheexperimentersknowwhichistheexperimentalgroupandwhichisthecontrol.如果”測量”是很確定的，如標準化問卷，則施測者主觀預期就無法影響。SelectingSubjects以大學生為對象的實驗結果之generalizability？代表性與因果關係可比性(comparability)最重要1Probabilitysampling(實驗法中難以使用)2Randomization(代表性？可比性？)3Matching，可配合配額抽樣的觀念，必要時，前測之後，再配對要之，使兩者在重要變項上的分佈一致OpenMatrixIllustrationRandomizationandMatching支持隨機化法：Maynotknowwhichvariableswillberelevantformatchingprocess.Moststatisticsusedtoanalyzeresultsassumerandomization.支持配對法：Randomizationonlymakessenseifyouhavealargepoolofsubjects.Question

______________isatechniqueforassigningexperimentalsubjectstoexperimentalandcontrolgroupsrandomly.nonprobabilityanalysesmatchingrandomizationnoneofthesechoicesAnswer:CRandomizationisatechniqueforassigningexperimentalsubjectstoexperimentalandcontrolgroupsrandomly.PreexperimentalResearchDesigns不夠專業的設計，或者，不知不覺中會這樣看事情One-shotcasestudy-singlegroupofsubjectsismeasuredonavariablefollowingexperimentalstimulus.One-grouppretest-posttestdesign-addsapre-testforthegroup,butlacksacontrolgroup.Static-groupcomparison-includesexperimentalandcontrolgroup,butnopre-test.One-ShotCaseStudyAmanwhoexercisesisobservedtobeintrimshape.One-GroupPretest-PosttestDesignAnoverweightmanwhoexercisesislaterobservedtobeintrimshapeStatic-GroupComparisonAmanwhoexercisesisobservedtobeintrimshapewhileonewhodoesn’tisobservedtobeoverweight.QuestionInaone-grouppretest-posttestdesign,whatislacking?EPSEManexperimentalgroupacontrolgroupnoneofthesechoicesAnswer:CInaone-grouppretest-posttestdesign,acontrolgroupislacking.SourcesofInternalInvalidity實驗所”發現”的結果其實不是來自實驗1Historicaleventsmayoccurduringthecourseoftheexperiment.2Maturationofthesubjects.實驗時間拉長的，會出現的問題3Testingandretestingcaninfluencebehavior.4Instrumentation，測驗不夠標準化時SourcesofInternalInvalidity5Statisticalregressionofsubjectsstartingoutinextremepositions.受試者一開始就是極端例外6Selectionbiases.選派兩組一開始就不可比7Experimentalmortality-subjectsdropoutofthestudybeforeit'scompleted.8因果不明(？)LimitingExternalInvaliditySolomonfour-groupdesignPosttest-onlycontrolgroupdesign9實驗污染：diffusionorimitationoftreatment實驗組與控制組有機會交通10compensation：予控制組額外補償，造成實驗之外的額外刺激11compensatoryrivalry:控制組的敵對補償性12Demoralizedcontrolgroupsubjects：控制組士氣消沉TheClassicalExperiment內在效度問題？在降低偏見的實驗：實：2<1；而控>實2以上可能造成內在效度的項目，有那些被解決？假設隨機分派過，則History?

Maturation?Testing??Instrument?Statisticalregression?Selectionbias?Experimentalmortality?Causaltimeorder?.......外在效度實驗結果可否概化至實際生活世界當中？測驗的情境與實驗刺激的互動偏見降低，因為受測引起接受實驗刺激的效果。在實際生活中，只有刺激而沒有受測SolomonFour-groupDesignFourgroupsofsubjects,assignedrandomly:Groups1and2arethecontrolandexperimentalgroup.Group3doesnothavethepre-test.Group4isonlyposttested.SolomonFour-groupDesignSolomonFour-groupDesignExpectedFindingsInGroup1,posttestprejudiceshouldbelessthanpretestprejudice.(後低於前)InGroup2,prejudiceshouldbethesameinthepretestandtheposttest.(前後相等)TheGroup1posttestshouldshowlessprejudicethantheGroup2posttestdoes.(1後低於2後)TheGroup3posttestshouldshowlessprejudicethantheGroup4posttestdoes.(後3低於後4)QuestionWhatisthebasicdifferencebetweentheclassicaldesignandtheSolomonfour-groupdesign?Thereisnodifference.TheSolomonfour-groupdesignrepeatstheclassicaldesignbutaddsgroupsthatarenotpretested.TheSolomonfour-groupdesignrepeatstheclassicaldesignbutaddsgroupsthatarenotposttested.Answer:BThebasicdifferencebetweentheclassicaldesignandtheSolomonfour-groupdesignisthattheSolomonfour-groupdesignrepeatstheclassicaldesignbutaddsgroupsthatarenotpretested.Posttest-onlyControlGroupDesignIncludesGroups3and4oftheSolomondesign.Withproperrandomization,onlythesegroupsareneededtocontrolproblemsofinternalinvalidityandtheinteractionbetweentestingandstimulus.嘿！奇怪的玩意兒！一個有趣的實驗

"Natural"ExperimentsImportantsocialscientificexperimentsoccuroutsidecontrolledsettingsandinthecourseofnormalsocialevents.Raisevalidityissuesbecauseresearchermusttakethingsastheyoccur.Web-basedExperimentsIncreasingly,researchersareusingtheWorldWideWebtoconductexperiments.Becauserepresentativesamplesarenotessentialinmostexperiments,researchersusevolunteerswhorespondtoinvitationsonline.ExperimentalMethodStrengths:Isolationoftheexperimentalvariableovertime.Experimentscanbereplicatedseveraltimesusingdifferentgroupsofsubjects.ExperimentalMethodWeaknesses:Artificialityoflaboratorysetting.Socialprocessesthatoccurinalabmightnotoccurinamorenaturalsocialsetting.QuickQuiz1.Experimentsareespeciallywellsuitedforresearchprojectsinvolving:limitedconceptswell-definedconceptshypothesistestingallofthesechoicesAnswer:DExperimentsareespeciallywellsuitedforresearchprojectsinvolvinglimitedconcepts,well-definedconceptsandhypothesistesting.2.A____________experimenteliminatesthepossibilityofaresearcherprejudgingresults.snowballdouble-blindpurposiveregressiveAnswer:BAdouble-blindexperimenteliminatesthepossibilityofaresearcherprejudgingresults.3.______________referstothepossibilitythattheconclusiondrawnfromexperimentalresultsmaynotaccuratelyreflectwhathasgoneonintheexperimentitself.ex