Wechsler Intelligence Scales and Testing

Wechsler Intelligence Scales

• Individually administered composite intelligence tests in a battery format assess intellectual abilities and allow personality observation.
• Recent versions (WAIS-IV and WISC-IV) offer an overall “Full Scale IQ” and index scores from subtest combinations.
• Psychometric soundness and relevant information renders these scales as some of the best psychological evaluations available for practitioners.
• Commonly used clinically.

Testing Intelligence: Pro and Con

• Intelligence testing has a history of misunderstanding, controversy, and misuse.
• Criticisms range from moral objections to accusations of cultural bias and test score abuse.
• Accurate prediction of future behavior stands as a primary asset in intelligence testing.
• Alfred Binet achieved early predictive success, refined further with increasing accuracy over time.
• IQ tests demonstrate excellent academic achievement and occupational performance predictions.
• Detects neuropsychological deficits.
• Classification of children into stereotyped categories becomes a liability.
• They are limited in predicting nontest activities and are sometimes used incorrectly.
• Reflects a person's current level of functioning and functions best in short-term predictions.
• Long-term predictions have accuracy problems stemming from uncontrolled variables.
• Relying solely on IQ scores for short-term academic placements risks failure due to crucial variables beyond test measurement.
• Users sometimes overextend test score meanings, especially in predictions.
• IQ scores correlate to occupation, ranging from highly trained professionals (mean IQs of 125) to unskilled workers (mean IQs of 87).
• Correlations between job proficiency and general intelligence are highest in complex jobs (.58) compared to less demanding ones (.23).
• General intelligence has moderately high correlations, for managers (.53), salespersons (.61), and clerks (.54).
• General intelligence accounts for ~50% of variance related to performance criteria in intellectually demanding tasks.
• Intelligence tests have financial efficacy for organizations in personnel selection.
• The accuracy of IQ tests improves when combined with integrity tests, work samples, and structured interviews.
• Provide cognitive strengths and weaknesses insights, valuable in standardized procedures, comparing age-related peers' performance.
• Useful comparisons are possible regarding a person's pattern of strengths and weaknesses.
• Individually administered tests offer examiners a structured context to observe how examinees approach cognitive tasks.
• Provides an initial impression of an individual's self-esteem, idiosyncrasies, anxiety, social skills, and motivation.
• Offers clinicians, educators, and researchers baseline measures for determining changes over time or comparing individuals in specific areas or abilities.
• Distinctions can evaluate program effectiveness or assess changing student abilities.
• Can help measure and follow cognitive changes in cases of head injury recovery or post-neurosurgery readjustment.
• Aids research/understanding on how environmental variables (educational programs, family background, and nutrition) affect cognitive functioning.
• Provides useful information on cultural, biological, maturational, or treatment-related differences among individuals.
• Emphasizes convergent, analytical, and scientific modes of thought, thus inherently biasing.
• Individuals who emphasize divergent, artistic, and imaginative modes of thought, face distinct disadvantages.
• Some critics state intelligence testing is a social mechanism to pass educational advantages to children of similar values.
• Not only places creative individuals at a disadvantage but also limits assessment of nonacademically oriented intellectual abilities, like social skills or practical intelligence.
• Social acumen, success in dealing with people, handling daily world realities, social fluency, and specific tasks are not measured on tests.
• People have more cognitive abilities than intelligence tests assess.
• Misunderstanding and misuse occur when scores are treated as measures of innate capacity.
• IQ is not an innate, fixed ability or representative of problem-solving in all situations.
• It is a limited sample, made at a point in time, on abilities can change because of certain circumstances.
• To a large extent it reflects the richness of past experiences.
• Despite interpretation guidelines being clear about a test's limitations, some have a inclination to view test results as absolute facts, and inherent characteristics.
• People want a quick, easy, and reductionist method to quantify, understand, and assess cognitive information, hence misuse.
• Largely unconcerned with underlying processes involved in problem-solving but focuses on end product/outcome instead of steps to the outcome.
• Uses “what” instead of "how."
• Low Arithmetic score might result from many factors: poor attention, failure to understand the examiner, or low educational attainment.
• Extreme "end product" emphasis occurs in the global IQ score.
• Complexity of cognitive functioning simplifies when an examiner views intellectual abilities as a global ability.
• A practitioner can quickly apply labels without examining specific strengths and weaknesses for interventions or recommendations.
• It detracts from the search for a wider, more precise, and process-oriented understanding of mental abilities.
• Involves limited usefulness in assessing minority groups with divergent cultural backgrounds.
• Test content has biases toward European American, middle-class values.
• Minorities at a disadvantage taking the tests resulting from deficiencies in motivation, poor practice, and culturally loaded items.
• Numerous arguments restricting the use of IQ scores.
• Traditional defenses of IQ scores propose less bias.
• Clinicians should remain aware of dilemmas, pay attention to subgroup norms, and cautiously interpret minority group IQ scores.
• Many feel their IQ is deeply personal, preferring others not have access.
• Problem compounded when IQ scores given to several persons during legal proceedings or personnel selection.
• Provides useful and well-respected functions.
• Accurately predicts short-term scholastic performance; assess strengths/weaknesses; predicts occupational achievement; and reveals personality variables.
• Enables the tracing of changes in an individual or population.
• Assets are helpful only given the understanding of the limitations of intelligence tests such as when tests fail to adequately predict certain aspects of occupational success/nonacademic skills.
• IQ scores do not measure innate, fixed ability, putting doubt into minority groups
• Overemphasis on end product/neglect in appreciating underlying cognitive processes.

History and Development

• During the 1930s, Wechsler initiated studying standardized tests, resulting in selecting 11 subtests for the initial battery.
• Wechsler's subtest search centered on his "global" perspective; intelligence is connected to the greater whole of personality.
• Stanford-Binet (Comprehension, Arithmetic, Digit Span, Similarities, and Vocabulary) accounted for several of Wechsler's derivatives.
• Picture Arrangement, Koh's Block Design (Block Design), Army Alpha (Information, Comprehension), Army Beta (Digit Symbol-Coding), Healy Picture Completion (Picture Completion), and Pinther-Paterson Test (Object Assembly) accounted for the remaining subtests.
• Subtests were combined and published in 1939 as the Wechsler-Bellevue Intelligence Scale, which had technical deficiencies.
• It has reliability problems related to the subtests coupled with size and sample representation.
• This influenced the 1955 revision to form the Wechsler Adult Intelligence Scale (WAIS).
• Another revision (WAIS-R) was published in 1981 based on 1,880 individuals representative of the 1970 census and categorized by age.
• WAIS-III supersedes WAIS-R to update the norms.
• Revision includes: age range extension, item modifications, developing a higher IQ ceiling/floor, decreasing timed performance reliance, development of index/factor scores, linkages to measures of cognitive achievement and extensive reliability/validity testing.
• Despite the changes, the WAIS-R's traditional verbal/performance features were maintained including the 6 Verbal subtests.
• Those clusters enable practitioners to measure the full scale.
• An added feature was inclusion of three new subtests, enabling calculation of four index scores offering more options and links.
• WAIS-IV is the most recent revision of the Wechsler intelligence scales (Wechsler, 2008a,b).
• Revision's goals are to update norms, improve the floors/ceiling, improve psychometric properties, reduce testing time, and conorm with the Wechsler Memory Scale–Fourth Edition (WMS-IV) and Wechsler Individual Achievement Test-II (WIAT).
• One obvious change is the elimination of verbal vs performance.
• The WAIS-IV uses the full IQ scale along with four index scores.
• A traditional measure had been "Verbal-Performance"
• The verbal IQ also can contain measures of verbal abilities with working memory, thus complicating
• Relying on four index scores ensures theoretically sound measures.
• Reliance parallels another assessment.
• It helps the client, especially with neurological solutions.
• Has new norms based on 2,200 persons between 16 and 90.
• Norms are derived from census data with subtests organized to core/supplemental
• Developed for mild cognitive impairment, borderline and special groups.
• The original Weschler-Bellevue was designd for children/
• New scores exist for below-average intelligence.

Major Changes on the WAIS-IV

• Elimination of Verbal and Performance IQs.
• Updated norms.
• 15 subtests (versus 14 on the WAIS-III).
• Full Scale IQ and Indexes based on 10 core subtests.
• General Ability Index is an optional index that combines Verbal Comprehension and Perceptual Reasoning.
• Three new subtests such as Visual Puzzles, Figure Weights, Cancellation.
• Two subtests were deleted such as Object Assembly, Picture Arrangement.
• Subtests organized according to core/supplemental.
• Included process scoring options for Block Design, Digit Span, Letter-Number Sequencing.
• Administration shortened with the 10 core subtests (for FSIQ & Indexes).
• Greater attention to floor and ceilings.
• Normed linkages with the Wechsler Memory Scale-IV.
• Upgrade for specialist neuropsychologists and geropsychologists.
• Deletion, addition, and subtest revision constitutes a further feature of the test.
• New norms have been developed for the WAIS-IV derived from 2,200 persons according to gender and ethnicity.
• Norms and responses developed for special groups.
• Wechsler developed the Wechsler Intelligence Scale for Children (WISC) so children could be assessed through items that are easier.

Organization of WAIS-IV Subtests

• Verbal Comprehension: Similarities, Vocabulary, Information. – Supplemental: Comprehension
• Perceptual Reasoning: Block Design, Matrix Reasoning, Visual Puzzles. –Supplemental: Figure Weights, Piture Completion
• Working Memory: Digit Span, Arithmetic. –Supplemental: Letter-Number Squencing
• Processing speed: Symbol Search, Coding. –Supplemental: Cancellation
• Original scales added for 2,200 European American boys selected to have 1940 data.
• The 1940 census had bias. The WISC-III added 4 factors.
• The WISC-IV contained more than any.The indexes had five subtests along with five new tests.
• Updated instruments were the WAIS and WISC-IV that update instrumentation.
• The intelligence has new subtes, especially working memory.

Major changes on the WISC-IV

– Elimination of Verbal/PErformance

• Updated Norms

Organization of WISC-IV indexes and subtests

• Verbal Comprehension contains: Similarities, Vocabulary, Comprehension. – Supplemental: INformation, World Resasoning
• Perceptual Reasoning contains Block Design, Picture Concepts, Matrix Reasoning –Supplemental: Pirture Completion
• Working Memory contains: Digit Span –Supplemental: Arithmetic
• processing Speed: Coding, Symbol Search – Supplemental: Cancellation
• Both the WISC and WAIS have adapted well.

Reliability and Validity

• WAIS-IV reliabilities are generally high (Wechsler, 2008b).
• FSIQ has split-half reliability of .98 (Wechsler, 2008b).
• Split-half reliabilities for the composite scores are slightly lower ranging from .96 for the Verbal to .90 for Processing.
• Split-half reliability, Vocabulary ( r = .94), Digit Span (r = .93) to (.78 for Cancellation) All except Cancellation above .81
• found not only for the standardization sample as well as clinical populations.
• Measurement for the scores indicates a small band.
• Test and restest for verbal is very high.

Reliability for the WISC-IV IS generally Excellent

• (M = .97) the mean internal consistencies for the individual index scores range from .91 to .92. The mean inter- nal consistencies for 12 of the 15 subtests ranged from a low of .79 for Symbol Search and Cancellation to a high of .90 for Letter-Number Sequencing. Test-retest reliability (average 32-day interval) for the Full Scale IQ was .89. The four index test-retest reli- abilities range from a high of .79 for Processing Speed to a relative low of .89 for Verbal Comprehension. Average test-retest stability for the subtests ranged from a high of .85 for Vocabulary to a low of .68 for Symbol Search. It should be noted, however, that this data represents reliabilities that were averaged across the 11 age groups. Reliabilities for cer- tain age groups can vary substantially. For example, 12 of the 15 subtest coefficients for the 6- to 7-year age group were found to be below .80.

Summary OF the reliability

• .87, Verbal Comprehension = .85, Perceptual Reasoning/Perceptual Organization Index = .70, Working Memory/Freedom from Distractibility = .74,Processing Speed = .81).
• Criterion validity has been performed on several Pearson Assessment WISC and Wais can be tested at high IQ.
• Factor analyses reflect index scores of the WISC and WAIS.
• The scales contain similar patters

Assets and Limitations

• Since initial publication, the Wechsler intelligence scales have been used in numerous research studies and have become widely used throughout the world. Thus, they are familiar to both researchers and practitioners and also have a long and extensive history of continued evaluation. This enormous research base allows practitioners to make relatively accurate predictions regarding clients. Inconsistencies between an individual's performance and rele- vant research can also be noted, alerting the practitioner that he or she needs to develop and pursue further hypotheses. Furthermore, the subtests are relatively easy to administer, and the accompanying manuals provide clear instructions, concise tables, and excellent norms.
• Adequate size and corresponds to demographic.
• Crossnational and AA and Hispanics sampling.
• WAIS Conformed to Wechsler.
• Extend the performance

Important aspect was the cognitive functioning levels.

• Clear data was also helpful.
• Helpful in assisting personality variables.
• One important criticisms was regarding the lack of the data. This includes Stanfor and academic for behavior.
• The instrument has several other features

Use of the Diverse Groups

• Acculturation
• Proficiency
• Competency
• Flexibility to occur.
• Test is used to the might be biased evaluation the such as Weschler intelligence scale such and the the assess.
• Bias assess groups for reasonable
• No bais for content and intelligence tesrs makes for the minoritt and the majorities

General for using with minorites.

• Make extra efforts
• Make to the insure
• Communication as clear as possible.
• Reources beyond greater significance with the diverse
• culture appears factor in lowering then deemphasize subtests the languages

Concerns towards native and america

• Should be the used to the some alternative.
• Tests and testing shouuld remain clear to provide

Meaning of IQ Scores

• Understand the level to the test and for negative attitudes.
• Misinterpretation.
• IQ is believed to fix and unchange with constance.

Many Factors can increase IQ

• In addition scores
• In addition to be a range.
• All tasks is in need to be take and tested on the ability

Various considerations when deciding if it is the best measurement to use

• The meaning of is more
• Can is a test. They each should always be assessed.
• There are various of the scores and can be used as a statistic.

Cautions and guidelines.

• Clarity has been done.
• There are mistakes and several factors that may contribute.

Errors can be found regarding the

• Failures to the query verbal.
• Record
• Poor reading and so forth.

What is the successive level of the Wais

• Each is needed in to be well versed.
• What is should test by reading them as well.
• What you should look at are there are.

The steps for interpretation.

• Make an Initial statement.
• elaborate
• The give

What are the principles/

• Successive begin aspects
• Greater useful
• level of signficatn
• Determine and or not. .The analysis needed.