Wechsler Adult Intelligence ScalesWechsler Adult Intelligence Scales

Wechsler Adult Intelligence Wechsler Adult Intelligence ScalesScales

David Wechsler devised adult intelligence David Wechsler devised adult intelligence test (1939)test (1939)

Now most widely used measure of Now most widely used measure of intelligence for adults and children intelligence for adults and children

IQ is calculated differentlyIQ is calculated differently IQ declines as people ageIQ declines as people age

Deviation IQDeviation IQ Compare scores to a normative sample Compare scores to a normative sample

of a similar ageof a similar age Mean = 100, SD = 15Mean = 100, SD = 15

Deviation IQ = (z-score * ) + x

= (z-score * 15) + 100

Deviation IQDeviation IQ

Average range: 85 to 115Average range: 85 to 115 ““Gifted” range: 130+Gifted” range: 130+ Mentally retarded: < 70Mentally retarded: < 70 How does that correspond to SD units?How does that correspond to SD units?

WAIS-IV SubtestsWAIS-IV Subtests

11 subtests, with 3 supplementary scales11 subtests, with 3 supplementary scales Full scale IQFull scale IQ Verbal IQVerbal IQ Performance IQPerformance IQ Index ScoresIndex Scores

Verbal ComprehensionVerbal Comprehension Perceptual OrganizationalPerceptual Organizational Working Memory Working Memory Processing Speed Processing Speed

Verbal SubtestsVerbal Subtests

Vocabulary (VC)Vocabulary (VC) Define wordsDefine words Best measure of GBest measure of G

Similarities (VC)Similarities (VC) Tell how two things are alikeTell how two things are alike Abstract verbal reasoningAbstract verbal reasoning

Information (VC)Information (VC) Questions of general knowledgeQuestions of general knowledge Crystalized intelligenceCrystalized intelligence

Verbal SubtestsVerbal Subtests

Arithmetic (WM)Arithmetic (WM) Solve arithmetic problems in your headSolve arithmetic problems in your head Working memory, mathematical reasoningWorking memory, mathematical reasoning

Digit Span (WM)Digit Span (WM) Repeat a list of numbers forwards and Repeat a list of numbers forwards and

backwardsbackwards Working memoryWorking memory

Performance SubtestsPerformance Subtests

Block Design (PO)Block Design (PO) Make designs using colored cubesMake designs using colored cubes Spatial and nonverbal reasoningSpatial and nonverbal reasoning

Matrix Reasoning (PO)Matrix Reasoning (PO) Given an incomplete pattern, choose from a Given an incomplete pattern, choose from a

number of options how to be complete a number of options how to be complete a picturepicture

Pattern recognition, non-verbal reasoningPattern recognition, non-verbal reasoning

Performance SubtestsPerformance Subtests

Digit Symbol Coding (PS)Digit Symbol Coding (PS) Paired associates Paired associates Each number has a mark put the mark that Each number has a mark put the mark that

goes with the numbergoes with the number Processing speed, learning ability or speed of Processing speed, learning ability or speed of

acquisitionacquisition

WAIS-IV SubtestsWAIS-IV Subtests

Each subtest assesses slightly different Each subtest assesses slightly different mental abilitiesmental abilities

All a measure of GAll a measure of G Multiple measures that assess multiple Multiple measures that assess multiple

abilities provides a comprehensive abilities provides a comprehensive measure of a person’s intelligencemeasure of a person’s intelligence

Highly reliable Highly reliable Test-retest correlation = .90 Test-retest correlation = .90