Introduction
WechslerIntelligenceScaleforChildren
WechslerIntelligenceScaleforChildren
ThescaleincludesspeechandoperationThe12subtestsofthecategory(seetable).
Thereareunequalnumberoftestquestionsundereachsubtest,arrangedinorderofdifficultylevel.Thescoringmethodis:firstlyevaluateandcalculatetherawscoresofeachsubtest,andthenconverttherawscoresofthetestscoredbythesubjectsintoscalescoresthroughtheirrespectiveagenorms.Finally,IQisstillusedasamarktoassessthetotallevelofintelligence.
ThereliabilityandvalidityofWexler’sintelligencescaleforschool-agechildrenarerelativelyhigh.ItisrecognizedinternationallyasanexcellentscaleforassessingintelligencethatgoeshandinhandwiththeStanford-BinetIntelligenceScale.TheWebster'sIntelligenceScaleforChildrenhasbeenrevisedinChina.
Testgroup
Ameasurementtoolforchildren'sintelligencefrom6to16yearsoldcreatedbyD.WexlerintheUnitedStates.ReferredtoasWISC.ItisdevelopedfromtheWexler-BenovoAdultIntelligenceTest.Thefirsteditionwaspublishedin1949,anditwasrevisedin1972withalargerstandardizedsamplegroup.Therevisededition(WISC-R)waspublishedin1974.Officiallyannouncedintheyear.Thereare2200peopleinthesample,withagesrangingfrom6yearsand0monthsto16yearsand11months,dividedinto11agegroups,eachwith200people,accordingtotheage,gender,race,region,andparentoccupationinthe1970NationalCensusoftheUnitedStates.Samplingoftheproportionsof6areasincludingresidence(urbanandrural).Therefore,thestandardizedsamplegroupadoptedbyWISC-Rhasgoodrepresentativeness.
Thecontentofthisscaleisrelativelydiversified,includingtwomajortypesoftests,speechandoperation.Thereare12sub-tests(seetable),thenumbersofwhicharetheorderinwhichthetestsarecarriedout.Amongthem,thetwosubtests11and12aresparetests,whichcanbereplacedwhenothersubtestscannotbeusedforsomereason.
WexlerIntelligenceScaleforSchool-ageChildren
Eachsubtesthasadifferentnumberoftestquestions(morethan30questions,suchascommonsenseandvocabulary,andasfewas4questions),Suchaspuzzles),arrangedinorderofdifficultylevel.
Evaluation
ThescoringmethodoftheWexlerSchool-ageChildren’sIntelligenceScaleistofirstevaluateandcalculatetheoriginalscoresofeachsubtest.Someofthesubtestsareonlybasedonthecorrectanswer.Pointsaregivenforsex,andsomesubtestsaregiventimesubsidypoints(suchaspicturearrangement,puzzles,buildingblockpatterns,etc.)takingintoaccountthespeedofcompletion.Then,theoriginalscoresofthetestscoredbythesubjectsareconvertedintoscalescoresthroughthenormsoftheirrespectiveages(scalescoresarestandardscoreswithameanof10andastandarddeviationof3,andtherangeis1-19).Thescalescoresof5speechtestsareaccumulatedintospeechscalepoints,andthescalescoresof5operationaltestsareaccumulatedintooperationscalepoints,andthetwoarecombinedintofullscalepoints.Finally,IQisstillusedasamarktoassessthetotallevelofintelligence.Here,thecalculationmethodofIQdoesnotuseratioIQ,butconvertstheabovescalescoresintoastandardscorewithameanof100andastandarddeviationof15──DeviationIQ.ThemainadvantageofusingdeviationIQisthatitsolvestheproblemthatthemeaningofIQscoresgeneratedbytheratioIQisnotconservedatallages,anditsscoresareeasytoconvertwithpercentilegrades.ThebasicmeaningofdeviationIQscoresisconsistentwiththetraditionalratioIQscores,sotheycanbecompared.
ThereliabilityandvalidityofWexler’sintelligencescaleforschool-agechildrenarerelativelyhigh.Itssplit-halfreliabilityrangesfrom.90to.96,andtheaveragecorrelationwiththeStanford-Binetscale(1972L-Mtype)is.73(fullscaleIQ).ItisrecognizedinternationallyasanexcellentscaleforassessingintelligencethatgoeshandinhandwiththeStanford-BinetIntelligenceScale.TheWexlerIntelligenceScaleforSchool-ageChildrenismoresuitableasatoolforclinicaldiagnosisandidentificationofmentalretardationthantheStanford-BinetIntelligenceScale.TheWexlerChildren’sIntelligenceScalehasbeenrevisedinChina.