Chapter 5.2: Intelligence Tests

Client’s needs

Clinical psychologists use a variety of intelligence tests and must carefully select ones that fit the _____.

For example, in school-related concerns, a test should help identify specific cognitive strengths and weaknesses without being overly influenced by behavioral problems.

Intelligence testing aims to compare an individual’s mental age (MA) with the performance of a standardization sample of the same chronological age (CA).

To ensure valid results, tests must be administered and scored in a highly standardized way using strict procedures. Any deviation can affect interpretation and important decisions such as educational placement or support services.

Binet scales; 1905

For many years, the _____ were among the most widely used intelligence tests.

Since Alfred Binet’s original work in ____, they have undergone multiple revisions.

Stanford-Binet Fifth Edition (2003)

The most recent version is the ____ (SB-5), published in ___ (Roid, ___).

The SB-5 consists of 10 subtests that assess both verbal and nonverbal abilities across five general cognitive factors, with one verbal and one nonverbal subtest for each factor:

Fluid reasoning, Quantitative reasoning, Visual-spatial processing, Working memory, Knowledge

Five general cognitive factors, with one verbal and one nonverbal subtest of SB-5

• _________ - the ability to solve novel problems.

• _______- the ability to solve numerical and word problems and understand basic numerical concepts.

• _____ - the ability to perceive spatial relationships, recognize orientation, and analyze patterns.

• _____ - the ability to temporarily hold and manipulate both verbal and nonverbal information.

• _____ - accumulated general information acquired through experience at home, school, work, or the environment.

2 years to adulthood

The SB-5 can be administered to individuals ranging from _____.

A key feature of the test is that it is adaptive. It begins with two routing subtests designed to estimate the appropriate level at which to begin the remaining subtests. Performance on these routing tasks determines the starting difficulty level for the rest of the assessment

Adaptive testing format

The SB-5 uses an ______ where difficulty is adjusted based on performance.

Individuals who perform well on early items receive more difficult questions, while those who struggle receive easier starting points.

Within each subtest, item difficulty gradually increases, and testing continues until the person can no longer answer correctly.

Higher performance leads to higher scores, which are also adjusted for age so that older individuals must answer more items correctly to achieve the same score as younger ones.

Verbal and non-verbal

The SB-5 includes ____ and ___ subtests.

____ tasks require language skills such as vocabulary, word memory, identifying objects (e.g., body parts, tools), and understanding numerical concepts.

_____ tasks reduce language demands and involve actions like pointing, assembling objects, copying designs, and identifying visual absurdities or patterns. These nonverbal components help ensure fair assessment for individuals with limited English proficiency.

The full test typically takes 15 to 75 minutes, depending on age and ability.

Reliability and validity

Research shows that the SB-5 has strong ____ and ____.

Internal consistency is very high (.95–.98 for IQ scores), and test-retest reliability is also strong (generally .80s for factor scores and .90s for IQ scores).

Validity evidence includes high correlations with other intelligence tests, such as .90 with the SB-4 and .84–.82 with the Wechsler scales. The SB-5 also effectively distinguishes individuals with learning disabilities, developmental disabilities, and ADHD from typically developing peers.

Binet-Simon; 1905

• First intelligence test

• Focus on mental age

• Binet & Simon (____)

Stanford-Binet (L-M); 1960

• Standardized in U.S.

• Introduced IQ formula

• Terman & Merrill

SB4; 1986

• 4-factor model

• Verbal & Nonverbal domains

• Thorndike et al.

SB5; 2003

• 5-factor CHC-based model

• Covers ages 2–85+, balanced verbal/nonverbal

• Roid (____)

Preparation

• Set up environment

• Quiet, rapport, appropriate starting point

• Groth-Marnat & Wright (2016)

Routing

• Determine starting level

• Based on age and ability

• Roid (2003)

Administration

• Conduct subtests

• Verbal & nonverbal tasks

• Roid (2003)

Scoring

• Convert scores

• Raw → Scaled → Composite IQ

• Sattler (2018)

Observation

• Record behavior

• Attention, motivation

• Groth-Marnat & Wright (2016)

Wechsler Scales; 1939

The _____ were developed by David Wechsler in _____ in response to limitations of early intelligence tests like the Stanford–Binet.

Wechsler-Bellevue Intelligence Scale; Verbal and Performance Scale

Wechsler designed the ______ specifically for adults, aiming to create a test with content that was more appropriate, engaging, and relevant to adult experiences rather than school-based material.

Unlike the Stanford– Binet, which organizes items by age levels, Wechsler tests group items into subtests arranged by increasing difficulty.

The original scale also introduced two major components—____ and _____ —allowing separate IQ scores for each, as well as a combined Full Scale IQ.

Wechsler Adult Intelligence Scale–Fourth Edition; 2008; 16 years and older

Over time, the Wechsler system was revised and expanded into a family of tests used across the lifespan.

The most widely used adult version today is the _____ (WAIS-IV), published in ____ and intended for individuals aged ____

Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index, Processing Speed Index

The WAIS-IV consists of 15 subtests designed to assess different aspects of cognitive functioning. These subtests are combined to produce a Full Scale IQ score as well as four Index scores, which provide a more detailed cognitive profile:

Four Index Scores:

_____ (VCI) – understanding and using language

____ (PRI) – visual-spatial reasoning and nonverbal problem solving

_____ (WMI) – attention, short-term memory, and mental manipulation

_____ (PSI) – speed and accuracy in visual scanning and simple decision tasks

This structure allows clinicians to identify specific cognitive strengths and weaknesses rather than relying solely on a single IQ score.

Vocabulary

(Verbal Comprehension)

The examinee defines increasingly difficult words. It is strongly related to overall IQ and is often considered a strong indicator of general intelligence (g).

Similarities

(Verbal Comprehension)

The examinee explains how two objects or concepts are alike. This measures abstract thinking and conceptual reasoning.

Arithmetic

(Working Memory)

Oral math problems are solved mentally without paper. This measures concentration and mental manipulation of numbers.

Digit Span

(Working Memory)

The examinee repeats sequences of numbers forward, backward, and in ascending order. This assesses short-term memory and attention control.

Information

(Verbal Comprehension)

General knowledge questions based on everyday learning and cultural exposure.

Comprehension

(Verbal Comprehension, supplemental)

Requires explanation of social rules, practical reasoning, and interpretation of common situations or proverbs. It measures common sense and judgment.

Letter-Number Sequencing

(Working Memory, supplemental)

Mixed sequences of letters and numbers must be reordered (numbers ascending, letters alphabetical), measuring attention and mental organization.

Picture Completion

(Perceptual Reasoning, supplemental)

Identify missing parts in pictures, requiring attention to detail and visual discrimination.

Coding

Processing Speed

The examinee copies symbols corresponding to numbers using a key under time pressure, measuring speed, accuracy, and visual-motor coordination.

Block Design

(Perceptual Reasoning)

Using colored blocks, the examinee replicates geometric designs. This measures spatial reasoning and visual-motor integration.

Matrix Reasoning

Perceptual Reasoning

Identify patterns and complete visual matrices. This measures abstract nonverbal reasoning.

Symbol Search

(Processing Speed)

Quickly determine whether target symbols appear in a set, measuring visual scanning speed and attention.

Visual Puzzles

(Perceptual Reasoning)

Select pieces that form a complete puzzle image, measuring mental rotation and spatial reasoning.

Figure Weights

(Perceptual Reasoning, supplemental)

Determine missing weights to balance a scale, assessing quantitative and analogical reasoning.

Cancellation

(Processing Speed, supplemental)

Mark target shapes within a visual field, measuring attention and processing speed under visual search conditions.

Psychometric support

The WAIS-IV has strong ____

Test-retest reliability across subtests ranges approximately from .74 to .90, depending on age and subtest.

The Index scores show strong internal consistency and stability over time.

Validity evidence is also strong: WAIS-IV scores correlate highly with other established cognitive measures. For instance, Working Memory Index scores correlate strongly with measures of attention and concentration, while Verbal Comprehension correlates highly with language fluency and comprehension tests.

These findings support its use as a reliable and valid measure of adult intelligence.

WISC-V; 1949; 2014; 6 to 17

The Wechsler system also includes a version for children called the ____ first developed in ____ and revised multiple times, with the latest edition published in ____.

It is designed for children aged ____ years and serves as a downward extension of the WAIS-IV.

Verbal comprehension, Visual-spatial ability, Fluid reasoning, Working memory, Processing speed

The WISC-V includes 10 primary subtests that generate five primary Index scores, similar in structure to the WAIS-IV. However, the Full Scale IQ is derived from a selected subset of these subtests rather than all ten.

These include measures of: ____, ____, ____, ____, ____.

The WISC-V is widely used in educational and clinical settings to assess learning difficulties, intellectual giftedness, and developmental disorders in children and adolescents.

Reliability and validity

The WISC-V demonstrates ____ and ____.

Its split-half reliability for the Full Scale IQ is very high at .96, indicating strong internal consistency. Reliability coefficients for the five primary Index scores range from .88 to .93, while individual subtests show reliability values between .80 and .94, suggesting consistent measurement across different parts of the test.

In terms of validity, the WISC-V shows strong correlations with other established measures of intelligence and academic achievement. It is also meaningfully related to measures of adaptive behavior, executive functioning, and emotional and behavioral functioning, indicating that it reflects broad aspects of a child’s cognitive and psychological functioning.

In practice, results from the WISC-V are interpreted to understand a child’s intellectual profile, academic abilities, and psychological functioning. These interpretations help psychologists identify strengths and weaknesses and are used to guide educational planning and interventions.

WAIS; 1955

• Wechsler IQ test

• First adult intelligence test

• Verbal IQ & Performance IQ

• Wechsler (____)

WAIS-R; 1981

Wechsler IQ test

• Updated norms

• Improved reliability & validity

• Wechsler (___)

WAIS-III; 1997

Wechsler IQ test

• Introduced Index Scores

• VCI, POI, WMI, PSI

• Wechsler (____)

WAIS-IV; 2008

Wechsler IQ test

• CHC-based structure

• Removed VIQ/PIQ; added PRI

• Wechsler (____); Flanagan & Kaufman (2009)

WAIS-V; 2020s

Wechsler IQ

• Digital + refined domains

• More focus on fluid reasoning & visual- spatial

• Pearson Clinical (___)

Preparation

WAIS Administration

• Set up testing environment

• Quiet room, rapport, consent

• Groth-Marnat & Wright (2016)

Administration

WAIS Administration

• Conduct subtests

• Follow standardized instructions strictly

• Wechsler (2008)

Scoring

WAIS Administration

• Convert scores

• Raw → Scaled → Index → FSIQ

• Sattler & Ryan (2009)

Observation

WAIS Administration

• Record behavior

• Note attention, effort, emotions

• Groth-Marnat & Wright (2016)

Using Intelligence Test in Clinical Practice

Intelligence tests are primarily used to estimate a person’s general intellectual ability (g).

Clinicians often use IQ scores as a baseline to compare against expected functioning, especially when assessing whether a child’s academic performance matches their cognitive potential.

This is useful in identifying whether learning difficulties are due to cognitive limitations, mental health concerns, or a gap between ability and achievement.

In some cases, such as Shane’s, academic performance may be lower than expected based on IQ, but still not meet criteria for a learning disability, suggesting other contributing factors like emotional distress or behavioral problems.

IQ testing is also useful in predicting academic success, as intelligence scores are generally associated with school performance. However, intelligence and academic achievement are not identical, and IQ should not be interpreted as a direct measure of scholastic ability alone.

Beyond scores, intelligence tests also provide insight into a person’s testing behavior and cognitive style. Clinicians observe factors such as motivation, anxiety, effort, and consistency during testing, all of which can influence performance.

External influences like sleep, medication, family pressure, or testing environment may also affect results. In some cases, individuals may even underperform intentionally to gain accommodations. Therefore, interpretation of IQ scores must go beyond numbers and include behavioral and contextual observations to fully understand the client’s functioning.