INTELLIGENCE AND PSYCHOLOGICAL TESTING

KEY CONCEPTS IN PSYCHOLOGICAL TESTING

• Psychological test: a standardized measure of a sample of a person’s behavior

• Measure individual differences that exist among people in abilities, aptitudes, interests, and aspects of personality

MENTAL ABILITY TESTS

• Most common• Include intelligence tests:

measure general mental ability---assess intellectual ability

• Aptitude tests: assess specific types of mental abilities

• Achievement tests: gauge a person’s mastery of knowledge and various subjects

PERSONALITY TESTS

• DEF: measure various aspects of personality, including motives, interests, values, and attitudes

STANDARDIZATION AND NORMS

• Standardization: refers to the uniform procedures used in the administration and scoring of a test

• Test norms: provide info about where a score on a psychological test ranks in relation to other scores on that test

• Percentile score: indicates the percentage of people who score at or below the score one has obtained

RELIABILITY

• Refers to the measurement consistency of a test

• Test-retest, split-half reliability

• Reliability estimates require computation of correlation coefficients: a numerical index of the degree of relationship btwn 2 variables

VALIDITY• Refers to the ability of a test to measure what it was

designed to measure• Content validity: degree to which the content of a test is

representative of the domain it’s supposed to cover• Criterion-related validity: estimated by correlating

subjects’ scores on a test with their scores on an independent criterion of the trait assessed by the test

• Construct validity: the extent to which there is evidence that a test measures a particular hypothetical construct

EVOLUTION OF INTELLIGENCE TESTING

GALTON’S STUDIES OF HEREDITARY GENIUS

• Sir Francis Galton• Found that success and eminence ran in families

• Wrote Hereditary Genius in 1869

• Coined the term nature vs. nurture

• Invented concepts of correlation and percentile test scores

BINET’S BREAKTHROUGH

• Alfred Binet asked to devise a test to identify mentally sub-normal children

• Worked with Theodore Simon

• The Binet-Simon scale expressed a child’s mental age: displays the mental ability typical of a child of a chronological age

TERMAN AND THE STANFORD-BINET

• Lewis Terman of Stanford expanded and revised Binet’s test

• 1916: Stanford-Binet Intelligence Scale

• Included intelligence quotient (IQ): a child’s mental age divided by chronological age, multiplied by 100

WECHSLER’S INNOVATIONS

• David Wechsler wanted a test for adults

• Wechsler Adult Intelligence Scale (WAIS) published in 1939

• Less dependent on verbal ability

• Discarded IQ in favor of normal distribution

INTELLIGENCE TESTING TODAY

• 2 categories:• Individual tests and group tests

• Individuals are time consuming and costly

• Schools use Otis-Lennon School Ability Test and Lorge-Thorndike Intelligence Test

BASIC QUESTIONS ABOUT INTELLIGENCE TESTING

WHAT KINDS OF QUESTIONS?

• Fairly diverse• Information, vocabulary, demonstrate memory

• Manipulate words, numbers, and images through abstract reasoning

WHAT DO MODERN IQ SCORES MEAN?

• Normal distribution: a symmetric, bell-shaped curve that represents the pattern in which many characteristics are dispersed in the population

• Scores translated into deviation IQ scores: locate subjects precisely within the normal distribution, using the standard deviation as the unit of measurement

• Scores indicate exactly where you fall in the normal distribution of intelligence

DO INTELLIGENCE TESTS MEASURE POTENTIAL OR KNOWLEDGE?

• Intelligence tests are intended to measure intellectual potential

• Reality: they measure both

DO INTELLIGENCE TESTS HAVE ADEQUATE RELIABILITY?

• Correlations range into the .90s

• They are reliable, but represent a sample

• Test anxiety can shift scores