Topic3ValidityValidityDefinition:Atestissaidtobevalidifitmeasuresaccuratelywhatitisintendedtomeasure.Typesofvalidity:

ContentvalidityCriterion-relatedvalidityConstructvalidityFacevalidity3.1Contentvalidity

Atestissaidtohavecontentvalidityifitscontentconstitutesarepresentativesampleofthelanguageskills,

structures,etc.withwhichitismeanttobeconcerned.Inordertojudgewhetherornotthetesthasacontentvalidity,weneedaspecificationoftheskillsorstructures,ect.thatitismeanttocover.AcomparisonoftestspecificationandtestcontentisthebasisforjudgmentsastocontentvalidityTheimportanceofcontentvalidityFirstly,thegreateratest’scontentvalidity,themorelikelytobeanaccuratemeasureofwhatissupposedtomeasure.Secondly,suchatest,atest-specificationsnotrepresentedatall,islikelytohaveaharmfulbackwasheffect.Areaswhicharenottestedarelikelytobecomeignoredinteachingandleaning.3.2

Criterion—relatedvalidity

(效標關聯效度)

Definition:ClassificationDefinition:

Anotherapproachtotestvalidityistoseehowfarresultsonthetestagreewiththoseprovidedbysomeindependentandhighlydependableassessmentofthecandidatesability.(CET摸擬題與CET實考題的各項分數的相關性)效標就是考察檢定考試效度的參照標準，效標關聯效度也就是與該參照標準有關的效度。效標關聯效度就是以某一種測驗分數與其效標分數之間的相關來表示的效度。換言之，一組考生參加某種考試的分數與同一組考生參加另一公認、的有較高效度的測驗結果的一致性程度就是該考試的效標效度。Therearetwokindsofcriterion—relatedvalidity:

ConcurrentvalidityConcurrent(共時性)validityisestablishedwhenthetestandcriterionareadministeredataboutthesametime.(例如:設計一次口語測試，因為沒有充足的時間去測試課程標準要求的全部語言功能，所以，對每位測試者進行10鐘的口試。但我們不能確定10分鐘的口試能否反映被試著的實際口語能力。我們先設計了一次考試，考試時間45分鐘，并覆蓋較多的語言功能，以此，建立了一個口試標準；再將著10分鐘的口語考試結果與這個標準作相關分析，然后確定這十分鐘的效度。）Anoralachievementtest

Courseobjectives

Alargenumberof‘functions’

45minutes10minutes?FulltestscoresshortenedtestscoresEvidenceforconcurrentvalidity:Degreeofagreementcalculationofdegreeofagreement:

correlationcoefficient(possiblevalue:-1~1,thehigherthebetter)1:perfect(positive)agreement0:zeroagreement-1:negativeagreementAtestoforalabilityforahighleveldiplomaticpostNotrationaltoruntheriskofappointingsomeonewithinsufficientoralabilityLoweragreementNOTallowedAbriefinterviewformingpartofaplacementtestLoweragreementallowedCalculatingcorrelationcoefficientinSPSS.PredictiveValidityThisconcernsthedegreetowhichatestcanpredictcandidates’futureperformance.e.g.Couldaproficiencytestpredictastudent’sabilitytocopewithagraduatecourseataBritishuniversity.Discussion:Validatingaplacementtest.How?3.3ConstructValidity(結構效度):Atest,partofatest,oratestingtechniqueissaidtohaveconstructvalidityifitcanbedemonstratedthatitmeasuresjusttheabilitywhichitissupposedtomeasure.Theword‘construct’referstoanyunderlyingability(ortrait)whichishypothesizedinatheoryoflanguageability.Forexample,whentestingreadingability,wehypothesizethattheabilitytoreadinvolvesasetofsub-abilities,suchasguessingunknownwordmeaningsfromthecontext.Thenweshouldrefertoresearchliteraturetoestablishwhetherornotsuchanabilityexistedandcouldbemeasuredinapartofthetest.

Ifwewereabletodemonstratethatwewereindeedmeasuringthatability,thenwesaythetesthasconstructvalidity.結構效度研究是一個搜集證據證實某一考試的確在測試我們想測試的那種心理屬性的過程。一個考試如果被證實是在測量我們想測量的那種能力，那么這個考試就具有較好的結構效度，它是一個編制假設再證實假設的過程。Howdoweknowthatthetestismeasuringwritingability?

Hypothesis:Ourtheoryofwritingtellsusthatunderlyingwritingabilityareanumberofsub-abilities:controlofpunctuationsensitivitytostylesstructurescoherenceandcohesion….Inordertomeasurethesesub-abilities,weadministerapilottestwhichinvolvestwosteps:用選擇題測試寫作能力（間接考試）步驟：找一組被試（第一次參加考試），對他們的寫作能力全面抽樣（讓他們做包含標點、語法、體裁等的選擇題）；把測試結果與范文相比較：如果結果與范文相關系數高，說明可以用選擇題測試寫作能力1.Weobtainextensivesamplesofthewritingabilityofthegrouptowhomtestisfirstadministered,andhavethesereliablyscored.2.Wethencomparescoresonthepilottestwiththescoresgivenforthesamplesofwriting.Iftheagreementishigh,wearemeasuringwritingabilitywiththetest.按照假設分別測量各項能力：假設：標點語法體裁寫作能力↙↓↘／∣﹨／∣﹨／∣﹨單選填空改錯單選填空改錯單選填空改錯7066685560628580823.4FaceValiditye.g.Anoraltestdoesn’trequirecandidatestospeakwouldnothavefacevalidity.Atestissaidtohavefacevalidityifitlook