Interpreting the WAIS-IV

Interpretation Overview Profile analysis Evaluate for differences between the four Indexes Determine whether the subtest scaled scores differ significantly from each other Obtain the base rates for differences between the Indexes Obtain the base rates for differences between some of the subtest scaled scores Determine base rates for inter-subtest scatter Develop hypotheses and make interpretations. MWM 9/22/2018

The Composites Full Scale Verbal Comprehension Perceptual Reasoning, Working Memory Processing Speed MWM 9/22/2018

Full Scale Global estimate of a adult's current level of cognitive ability Usually the most reliable and valid estimate of the adult's intellectual ability. Provides information about the adult's relative standing in the general (standardization) population Usually used to obtain a descriptive classification of the adult's IQ level Very Superior Superior High Average Average Low Average Borderline Extremely Low; see Converting the Full Scale IQ to a percentile rank often helpful in explaining it to individuals unfamiliar with standard scores Use the Full Scale IQ as the primary index of a adult's intellectual ability unless there is a compelling reason to use one of the Indexes MWM 9/22/2018

Verbal Comprehension Measures Oral input (questions) application of verbal skills and information to the solution of new problems ability to process verbal information ability to think with words crystallized knowledge cognitive flexibility (including the ability to shift mental operations) ability to self-monitor. Oral input (questions) Oral output (answers) Nonverbal factors-such as forming a mental picture of the words or questions-also may playa role in solving Verbal Comprehension tasks. MWM 9/22/2018

Perceptual Reasoning Measures ability to think in terms of visual images and manipulate them with fluency cognitive flexibility (including the ability to shift mental operations) relative cognitive speed, ability to interpret or organize visually perceived material within a time limit nonverbal ability ability to form abstract concepts and relationships without the use of words fluid reasoning, ability to self-monitor. The four subtests Verbal factors also may play a role in solving Perceptual Reasoning tasks. using verbal descriptions in thinking about blocks and block placement categorizing the pictures into logical groups on Picture Concepts Using verbal processing to solve Matrix Reasoning problems verbally identifying parts of objects on Picture Completion MWM 9/22/2018

Working Memory Measures short-term memory the ability to sustain attention, Numerical ability encoding ability, auditory processing skills Cognitive flexibility (including the ability to shift mental operations), Ability to self-monitor. Verbal and nonverbal factors play a role in solving Working Memory tasks. MWM 9/22/2018

Processing Speed Measures Processing speed rate of test taking perceptual discrimination speed of mental operation, psychomotor speed attention Concentration short-term visual memory visual-motor coordination, numerical ability, cognitive flexibility (including the ability to shift mental operations) ability to self-monitor. MWM 9/22/2018

Profile Analysis Looks at a adult's unique ability pattern, going beyond the information contained in the Full Scale IQ or Indexes Knowledge of ability patterns can help in formulating teaching strategies and other types of interventions. The Full Scale IQ is a valuable measure of general intellectual ability Tells us little about the specific underlying abilities on which it is based. Examining the subtest scale scores can show strengths or weaknesses. MWM 9/22/2018

Example Profiles 1. A flat profile with all subtest scaled scores far above average (e.g., from 14 to 16) suggests that a adult is intellectually gifted and may profit from instruction that capitalizes on the adult's exceptional intellectual skills. 2. A flat profile with all subtest scaled scores far below average (e.g., from 2 to 4) suggests that a adult has limited intellectual ability and needs specialized instruction appropriate for the adult's low level of functioning. 3. A variable profile, with subtest scaled scores varying over a large range of scaled scores (e.g., from 3 to 16), suggests that a adult has unique strengths and weaknesses and may benefit from specialized instruction designed to capitalize on the strengths and remediate the weaknesses. 4. A profile of subtest scaled scores within normal limits (e.g., from 8 to 12) suggests average ability across all areas measured and suggests that a adult needs a standard program of instruction. The goal of profile analysis is to generate hypotheses about a adult's abilities, which then need to be checked against other information about the adult (e.g., parent and teacherreports, records of academic performance). MWM 9/22/2018

The simplest approach to subtest profile analysis Evaluate subtest scores in reference to the norm group A mean of 10 with a standard deviation of 3 serves as the reference point for the norm group. You can describe subtest scaled scores using a categorical approach Subtest scaled scores of 13 to 19 always indicate a strength (one to three standard deviations above the mean). Subtest scaled scores of 8 to 12 always indicate average ability (within one standard deviation of the mean). Subtest scaled scores of I to 7 always indicate a weakness (one to three standard deviations below the mean). MWM 9/22/2018

Significant Differences In applying a “significant difference” approach, you will need to answer questions like the following: Do the Indexes of interest differ significantly from each other (e.g., Verbal Comprehension vs. Perceptual Reasoning)? Do the subtest scaled scores of interest differ significantly from each other (e.g., Vocabulary vs. Block Design)? Do the subtest scaled scores of interest differ significantly from the mean of their respective Composites (e.g., Similarities vs. the Verbal Comprehension mean)? Do the subtest scaled scores of interest differ significantly from the mean of the other subtests administered (e.g., Similarities vs. the mean of the other nine subtests administered)? Whatever comparisons you choose to make you must determine whether the differences are statistically significant (i.e., too large to be likely to have occurred by chance). MWM 9/22/2018

Base Rates A second approach to profile analysis is to determine the frequency with which the differences between scores in a adult‘s prolile occurred in the standardization sample; this is called the Base rate Approach or the Probability of Occurrence Approach. MWM 9/22/2018

Primary Methods of Profile Analysis Compare the VCI, PRI, WMI, and PSI with each other. Compare the subtest scaled scores within each Composite with the adult's mean scaled score for that Composite and for the Full Scale. This is where we stop for the WAIS assignment. Compare sets of individual subtest scaled scores (i.e., planned paired comparisons). Compare the range of subtest scaled scores with the base rate found in the standardization sample. Compare sets of individual Process scaled scores. Compare Process scaled-score differences with the base rates found in the standardization sample. MWM 9/22/2018

VCI > PRI Hypotheses Verbal comprehension skills are better developed than perceptual reasoning skills. Verbal processing is better developed than visual-spatial processing. Auditory-vocal processing is better developed than visual discrimination processing. Knowledge acquired through accumulated experience is better developed than knowledge needed to solve nonverbal problems. Retrieval of verbal information from long-term memory is better developed than nonverbal problem solving. Crystallized knowledge is better developed than fluid reasoning. MWM 9/22/2018

PRI > VCI Hypotheses • Perceptual reasoning skills are better developed than verbal comprehension skills. Visual-spatial processing is better developed than verbal processing. Visual-discrimination processing is better developed than auditory-vocal processing. Knowledge needed to solve nonverbal problems is better developed than knowledge acquired through accumulated experience. Nonverbal problem solving is better developed than retrieval of verbal information from long-term memory. Fluid reasoning is better developed than crystallized knowledge. MWM 9/22/2018

VCI > WMI Hypotheses Verbal comprehension is. better developed than working memory. Verbal processing is better developed than short-term auditory memory. Auditory-vocal processing is better developed than use of encoding strategies. Long-term verbal memory is better developed than short- term auditory memory. Retrieval of verbal information from long-term memory is better developed than retrieval of information from short- term memory. Crystallized knowledge is better developed than short-term auditory memory. MWM 9/22/2018

WMI > VCI Hypotheses Working memory is better developed than verbal comprehension. Short-term auditory memory is better developed than verbal processing. Use of encoding strategies is better developed than auditory-vocal processing. Short-term auditory memory is better developed than long-term verbal memory. Retrieval of information from short-term memory is better developed than retrieval of verbal information from long- term memory. Short-term auditory memory is better developed than crystallized knowledge. MWM 9/22/2018

VCI > PSI Hypotheses Verbal comprehension is better developed than processing speed. Verbal processing is better developed than speed of mental operation. Auditory-vocal processing is better developed than visualmotor coordination. Processing of verbal stimuli is better developed than processing of nonverbal stimuli. Long-term verbal memory is better developed than short- term visual memory. Crystallized knowledge is better developed than processing speed. MWM 9/22/2018

PSI > VCI Hypotheses Processing speed is better developed than verbal comprehension. Speed of mental operation is better developed than verbal processing. Visual-motor coordination is better developed than auditory-vocal processing. Processing of nonverbal stimuli is better developed than processing of verbal stimuli. Short-term visual memory is better developed than long- term verbal memory. Processing speed is better developed than crystallized knowledge. MWM 9/22/2018

PRI > WMI Hypotheses Perceptual reasoning is better developed than working memory. Visual-spatial processing is better developed than short-term auditory memory. Immediate problem-solving ability is better developed than use of encoding strategies. Interpretation or organization of visually perceived material is better developed than short-term auditory memory. MWM 9/22/2018

Compare Sets of Individual Subtest Scaled Scores Digit Span vs. Letter Number Sequencing Coding vs. Symbol Search Similarities vs. Picture Concepts MWM 9/22/2018

DS vs LN DS > LN LN > DS This pattern may suggest that short-term auditory memory for tasks that require rote memorization with minimal information processing is better developed than short-term auditory memory for tasks that require rote memorization and information processing. LN > DS This pattern may suggest that short-term auditory memory for tasks that require rote memorization and information processing is better developed than short- term auditory memory for tasks that require rote memorization with minimal information processing. MWM 9/22/2018

CD vs. SS CD > SS SS > CD This pattern may suggest that visual-perceptual symbol- associative skills are better developed than visual- perceptual discrimination skills that do not involve association. SS > CD This pattern may suggest that visual-perceptual discrimination skills that do not involve association are better developed than visual-perceptual symbol- associative skills. MWM 9/22/2018

SI vs. PCn SI >PCn PCn > SI This pattern may suggest that abstract reasoning ability with verbal stimuli is better developed than abstract reasoning ability with visual stimuli involving familiar objects. PCn > SI This pattern may suggest that abstract reasoning ability with visual stimuli involving familiar objects is better developed than abstract reasoning ability with verbal stimuli. MWM 9/22/2018

Subtest Descriptions: How to Talk about Strengths and Weakneses When you begin comparing individual subtest scores to the mean of either all 10 subtest SSs or the mean of the VCI and PRI, you need to have a wide vocabulary at your disposal to describe the examinee’s strength or weakness. You want to be able to put into layman’s terms what cognitive domains, skills, and abilities each subtest taps into. Chapter 14 in the Flanagan and Harrison book have very good descriptions for all the Wechsler measures and to the extent the WAIS-IV overlaps both the old WAIS-III and the WISC-IV, you need to draw upon their information. MWM 9/22/2018

Subtest Descriptions To supplement the lack of an independent textbook for the WAIS-IV, you are welcome to augment the missing data points in a variety of ways. The administration manual is an excellent resource. I have posted links to some of Pearson’s training materials on the “Lectures” page of our class website I have sumarized information from a variety of sources and relied heavily upon the material distributed by Pearson. MWM 9/22/2018

Verbal Comprehension Subtests MWM 9/22/2018

Similarities Verbal concept formation and reasoning Also involves Crystallized intelligence Abstract reasoning Auditory comprehension Memory Associative and categorical thinking Distinction between nonessential and essential features Verbal •Degree of abstraction is an critical in score determinant MWM 9/22/2018

Vocabulary Word knowledge and verbal concept formation. It also measures an examinee’s crystallized intelligence, fund of knowledge, Learning ability, long-term memory, and the degree of language development. Other abilities that may be used auditory comprehension and verbal expression MWM 9/22/2018

Information •Measures ability to acquire, retain, and retrieve general factual knowledge. Also involves crystallized intelligence and long-term memory. Other skills that may be used include verbal perception, verbal comprehension verbal expression MWM 9/22/2018

Perceptual Reasoning Subtests MWM 9/22/2018

Block Design Measures the ability to analyze and synthesize abstract visual stimuli. It also involves nonverbal concept formation and reasoning, broad visual intelligence, fluid intelligence, visual perception and organization, simultaneous processing, visual-motor coordination, learning, and the ability to separate figure-ground in visual stimuli MWM 9/22/2018

Matrix Reasoning Involves fluid intelligence, broad visual intelligence, classification and spatial ability, knowledge of part-whole relationships, simultaneous processing, and perceptual organization MWM 9/22/2018

Visual Puzzels -- New Visual Puzzles–examinee views a completed puzzle, and selects the 3 pieces from an array to make that puzzle Designed to measure nonverbal reasoning ability to analyze and synthesize abstract visual stimuli. Similar measures involve visual perception, broad visual intelligence, fluid intelligence, simultaneous processing, Spatial visualization and manipulation, and the ability to anticipate relationships among parts MWM 9/22/2018

Working Memory Subtests MWM 9/22/2018

Digit Span – New and Improved Key changes Added sequencing task Eliminated phonetically similar intra-trial numbers All three tasks contribute to Digit Span subtest score Because of the changes, the shift from one Digit Span task to another reflects cognitive flexibility and mental alertness. Copyright © 2007 Pearson Education, inc. or its affiliates. All rights reserved. Why Add DS Sequencing? •DS score criticized -Forward doesn’t really place much of a demand on WM until later trials –has to chunk or use strategies •Sequencing increases load of working memory for the DS subtest •All three still administered: –Forward provides floor for low ability examinees –Forward also seems to be a warm-up precursor task for –Backward DS •lost floor on Backward when Forward wasn’t given in a pilot study –Sequencing increases load of working memory and added to ceiling MWM 9/22/2018

Digit Span Forward Involves rote learning and memory, attention, encoding, and auditory processing. MWM 9/22/2018

Digit Span Backward Involves working memory, transformation of information, mental manipulation, and viso-spatial- imaging MWM 9/22/2018

Digit Span Sequencing Is similar to other tasks that are designed to measure working memory and mental manipulation MWM 9/22/2018

Arithemetic Measures May also involve mental manipulation concentration, attention, short-and long-term memory, numerical reasoning ability, and mental alertness May also involve sequential processing fluid, quantitative, and logical reasoning quantitative knowledge Omitted references to English measurement system and currency Decreased emphasis on mathematical skills to increase emphasis on working memory MWM 9/22/2018

Processing Speed Subtests PSI subtests measure the speed of mental and grapho-motor-processing MWM 9/22/2018

Symbol Search One of most important uses for this subtest is score comparison with Coding Allows pulling out fine motor (grapho-motor) speed from mental processing speed. MWM 9/22/2018

Coding Measure the speed of mental and grapho-motor- processing MWM 9/22/2018

References The slides discussing and describing the WAIS-IV subtests were developed by heavily drawing up a slide show published by Pearson Assessment. MWM 9/22/2018