1. David Wechsler (January 12, 1896 - May 2, 1981) was a leading American psychologist. He
developedwell-knownintelligence scales,includingthe WechslerAdultIntelligence Scale (WAIS)
and the WechslerIntelligence Scale forChildren(WISC).Wechslerisalsoknownfor establishing
the deviationquotient,or DQ, which replaced the use of mental ages in testing an individual’s
intelligence. A student of both Karl Pearson and Charles Spearman, Wechsler was also greatly
influencedby EdwardL. Thorndike.Updatedversions of Wechsler’s intelligence tests continue
to remain popular in the twenty-first century.
Wechslerviewed intelligenceasan effectratherthana cause,and believedformerassessments
of general intelligence tobe toonarrow.Instead,he foundthatnon-intellectual factors, such as
personality,oftencontribute tothe development of an individual’s intelligence. For Wechsler,
intelligence should be regarded not just as the ability to think rationally, although that was a
significant component. Equally important in his conception was the ability to act purposefully
and effectively in one's environment. Thus, he regarded the measure of intelligence to go
beyond intellectual capacity into the realm of activity in the world, a measure that has much
greaterusefulness.Wechsler'sworkhassignificantlyincreasedourappreciationfor what makes
for a successful individual.
Intelligence Scales
While working at the Bellevue Psychiatric Hospital, Wechsler published various intelligence
scales.The renownedWechslerAdultIntelligenceScale (WAIS) was developed first in 1939 and
termedthe Wechsler-BellevueIntelligence Test.Fromthishe derivedthe Wechsler Intelligence
Scale for Children(WISC) in1949 and the Wechsler Preschool and Primary Scale of Intelligence
(WPPSI) in 1967. Wechsler originally created these tests to find out more about his patients at
the Bellevue clinic; he found the then-popular Stanford-Binet IQ test unsatisfactory.
http://www.newworldencyclopedia.org/entry/David_Wechsler
Wechsler Adult Intelligence Scale--Revised
Purpose:Designedasa comprehensive testof cognitiveabilityforadults.
Population:Ages16 and over.
Score: Verbal IQ,Performance IQ,andFull Scale IQ.
Time: (60-90) minutes.
Author: DavidWechsler.
Publisher:The Psychological Corporation.
Description:The WechslerAdultIntelligence Scale-Revised(WAIS-R) isageneral testof
intelligence,whichWechslerdefinedas,"...the global capacityof the individual toact

2. purposefully,tothinkrationally,andtodeal effectivelywithhisenvironment."Inkeepingwith
thisdefinitionof intelligence asanaggregate of mental aptitudesorabilities,the WAIS-R
consistsof 11 subtestsdividedintotwoparts,verbal andperformance.
Scoring: The WAIS-Rconsistsof six verbal subtestsandfive performance subtests.The verbal
testsare: Information,Comprehension,Arithmetic,DigitSpan,Similarities,andVocabulary.The
Performance subtestsare:Picture Arrangement,Picture Completion,BlockDesign,Object
Assembly,andDigitSymbol.The scoresderivedfromthistestare a Verbal IQ(VIQ),a
Performance IQ(PIQ),anda Full Scale IQ(FSIQ).The FSIQisa standardscore witha mean of 100
and a standarddeviationof approximately15.
Reliability:Correctedsplit-half reliabilitycoefficientsforVerbal IQ(.95to .97) andFull Scale IQ
(.96 to .98), and theirrespective standarderrorsof about2 points,are quite acceptable.The
reliabilityof Performance IQisexcellent,averaging.93,althoughthe value of .88 at ages16 to
17 is notideal.Subtestreliabilitycoefficientsaverage valuesexceed.80for9 of the 11 subtests.
OnlyPicture Arrangement(.74) andObjectAssembly(.68) fall shortof expectations.Test-retest
reliabilitycoefficientsaffirmthe excellentreliabilityof the Verbal andFull Scales,andshow
Performance IQtobe quite acceptable (.89to .90). Test-retestcoefficientsforthe subtests
confirmthe reliabilityof all tasksexceptObjectAssembly andPicture Arrangement.
Validity:The manual for thisrevisededitiondoesnotprovidenew validitydata,butrefers
interestedpersonstothe manual forthe original WAIS.
Norms: The total sample,comprising1,880 individuals,wascarefullystratifiedon the variables
of sex,race (white-nonwhite),geographicregion,occupationalgroup,educational attainment,
and urban-rural residence.The nine age groupsrangedinsize from160 to 300.
SuggestedUses:The WAIS-Risrecommendedforuse inclinical,educational,andresearch
settings.
Reference:http://www.cps.nova.edu/~cpphelp/WAIS-R.html