intelligence and psychological testing. key concepts in psychological testing psychological test: a...
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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