Module 38: Assessing intelligence

intelligence test

a method for Assessing an individual’s mental aptitudes and comparing them with those of others, using numerical scores

achievement test

a test designed to assess what a person has learned

aptitude test

a test designed to predict a person’s future performance; aptitude is the capacity to learn

Francis Galton

In the late 1800s, Francis Galton, who believed that genius was inherited, attempted but failed to construct a simple intelligence test. His hope had been to identify those with exceptional skills and encourage them to reproduce

Alfred Binet

In France in 1904, Alfred Binet, who tended toward an environmental explanation of intelligence differences, started the modern intelligence-testing movement by developing questions to measure children’s mental age and thus predict progress in the school system. Binet hoped his test would be used to improve children’s education rather than to limit their opportunities

Mental age

a measure of intelligence test performance devised by Binet; the level of performance typically associated with children of a certain chronological age. Thus, a child who does as well as an average 8-year-old is said to have a mental age of 8

Lewis Terman

tried the Paris-developed questions and age norms with California students. For Terman, intelligence tests revealed the intelligence with which a person was born

Stanford-Binet

the widely used American revision (by Terman at Stanford) of Binet’s original intelligence test

intelligence quotient (IQ)

Derived by German psychologist William Stern. Defined originally as the ratio of mental age (ma) to chronological age (ca) multiplied by 100 (thus IQ = ma/ca x 100). On contemporary intelligence tests, the average performance for a given age is assigned a score of 100

David Wechsler

created what is now the most widely used intelligence test, the Wechsler Adult Intelligence Scale (WAIS)

Wechsler Adult Intelligence Scale (WAIS)

the WAIS and its companion versions for children are the most widely used intelligence tests; they contain verbal and performance (nonverbal) subtests. Yields an overall score and individual scores for verbal comprehension, perceptual organization, working memory, and processing speed.

WISC

Wechsler Intelligence Scale for Children

Standardization

defining uniform testing procedure and meaningful scores by comparison with the performance of a pretested group

normal curve

the bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes

reliability

the extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test, on alternative forms of the test, or on retesting

validity

the extent to which a test measures or predicts what it is supposed to

content validity

the extent to which a test samples the behavior that is of interest

predictive validity

the success with which a test predicts the behavior it is designed to predict; it is assess by comparing the correlation between test scores and the criterion behavior (Also called criterion-related validity)