(3) The Wechsler Scales and Intelligence Across the Lifespan

Vocabulary practice flashcards covering David Wechsler's definition of intelligence, the Wechsler Scales (WAIS, WISC, WIPPSI), individual subtests, scoring indices, score interpretations, and SB5 CHC factors.

Intelligence (Wechsler Definition)

The aggregate or global capacity of the individual to act purposefully, think rationally, and deal effectively with their environment.

Wechsler Scales

Intelligence tests created in response to reliance on a single score or general mental ability ($g$), noted for using a Point Scale and introducing the Nonverbal Performance Scale.

Point Scale

A scoring arrangement in which specific credits or points are awarded for each item within a subtest, forming individual subtest scores that combine to make up the overall score.

Full Scale IQ (FSIQ)

The overall composite score derived from Wechsler subtests, structured with a mean of $100$ and a standard deviation of $15$.

Verbal IQ

An index reflecting verbal comprehensive abilities, educational proficiency, verbal memory, verbal fluency, and the capacity to work with abstract symbols; highly dependent on educational background.

Performance IQ

An estimate of perceptual organizational abilities, nonverbal contact with the environment, ability to integrate perceptual stimuli with motor responses, capacity to work in concrete situations, and speed (with all subtests timed).

General Ability Index (GAI)

An index of intellectual ability derived specifically from verbal comprehension and perceptual reasoning subtests.

Cognitive Proficiency Index (CPI)

An index measured through working memory and processing speed that highlights learning disabilities when deficits in these areas are present.

WIPPSI (WPPSI)

Wechsler Preschool and Primary Scale of Intelligence, designed for children aged $4$ years to $6$ years $6$ months ($4$ to $6\frac{1}{2}$ years old).

WISC

Wechsler Intelligence Scale for Children, designed for individuals aged $6$ to $17$ years old.

WAIS

Wechsler Adult Intelligence Scale, designed for individuals aged $18$ to $75$ years old.

Vocabulary Subtest

A core subtest assessing vocabulary level and maintained abilities; it remains relatively stable and is one of the last cognitive functions to deteriorate.

Similarities Subtest

A core subtest evaluating abstract thinking by asking examinees to identify the underlying commonality between pairs of seemingly dissimilar words or concepts of increasing difficulty.

Arithmetic Subtest

A core subtest measuring concentration through approximately $15$ arithmetic word problems arranged in increasing order of difficulty.

Digit Span Subtest

A core subtest evaluating immediate memory and anxiety by requiring the examinee to repeat sequences of digits at a rate of one per second, administered both forward and backward.

Information Subtest

A core subtest measuring range of knowledge, environmental alertness, and cultural opportunities; it is culturally-dependent.

Comprehension Subtest

A Wechsler subtest assessing practical judgment, social conventionality, and common sense through questions concerning practical emergencies, social customs, and proverbs.

Letter-Number Sequencing Subtest

A subtest measuring working memory and attention by asking subjects to reorder mixed sequences of numbers and letters into sequential and alphabetical order.

Digit Symbol-Coding Subtest

A timed subtest assessing visual-motor functioning and processing speed by having the subject copy symbols that match corresponding numbers.

Block Design Subtest

A timed subtest assessing spatial analysis, visual-motor integration, abstract concept formation, and neurocognitive impairment using $9$ red-and-white blocks to replicate printed patterns.

Matrix Reasoning Subtest

A core subtest evaluating inductive reasoning and nonverbal problem-solving where subjects identify the rule or pattern in an incomplete matrix and select the correct missing piece.

Symbol Search Subtest

A subtest assessing information-processing speed by requiring the subject to visually scan a search group to determine if target geometric symbols are present.

Fluid Reasoning (FR)

The SB5 factor corresponding to CHC Fluid Intelligence ($Gf$), measuring novel problem-solving and understanding of non-culturally bound relationships (e.g., Matrices, Verbal Analogies).

Knowledge (KN)

The SB5 factor corresponding to CHC Crystallized Knowledge ($Gc$), assessing skills and knowledge acquired through formal and informal education (e.g., Picture Absurdities, Vocabulary).

Quantitative Reasoning (QR)

The SB5 factor corresponding to CHC Quantitative Knowledge ($Gq$), evaluating mathematical thinking, number concepts, and numerical estimation.

Visual-Spatial Processing (VS)

The SB5 factor corresponding to CHC Visual Processing ($Gv$), involving the perception of patterns, relationships, spatial orientation, and gestalt among visual stimuli (e.g., Position and Direction, Form Board).

Working Memory (WM) [SB5]

The SB5 factor corresponding to CHC Short-Term Memory ($Gsm$), evaluating the temporary storage, transformation, and sorting of information in memory.

Scaled Score: 0 to 3

The Wechsler subtest scaled score classification interpreted as impaired, hampered, or greatly affected.

Scaled Score: 4 to 6

The Wechsler subtest scaled score classification interpreted as poor.

Scaled Score: 7 to 8

The Wechsler subtest scaled score classification interpreted as slightly lowered or fair.

Scaled Score: 9 to 10

The Wechsler subtest scaled score classification interpreted as adequate or average.

Scaled Score: 12 and up

The Wechsler subtest scaled score classification interpreted as above par.

Very Superior

An intelligence classification for IQ scores of $130+$; also known by the value-neutral term 'Higher extreme above average.'

Superior

An intelligence classification for IQ scores ranging from $120-129$; also designated by the value-neutral term 'Well above average.'

High Average

An intelligence classification for IQ scores ranging from $110-119$.

Average (Intelligence Classification)

An intelligence classification denoting IQ scores in the range of $90-109$.

Low Average

An intelligence classification denoting IQ scores in the range of $80-89$.

Borderline

An intelligence classification for IQ scores ranging from $70-79$; also referred to by the value-neutral term 'Well below average.'

Extremely Low / Intellectually Deficient

An intelligence classification designating IQ scores of $69\text{ and below}$; also termed 'Lower extreme.'