Assessing Intelligence Module 31 Assessing Intelligence Worth Publishers

Assessing Intelligence One-Minute Intelligence Test

Origins of Intelligence Testing Alfred Binet – French Psychologist developed intelligence test when schools needed a way to objectively identify students with special needs believed that all children follow same path of development, some develop more rapidly

Origins of Intelligence Testing Mental Age a measure of intelligence test performance devised by Binet chronological age that most typically corresponds to a given level of performance child who does as well as the average 8-year-old is said to have a mental age of 8

Origins of Intelligence Testing Stanford-Binet the widely used American revision of Binet’s original intelligence test revised by Terman at Stanford University extended range to include adults Developed test to evaluate immigrants and WWI army recruits – cultural bias

Origins of Intelligence Testing Intelligence Quotient (IQ) defined originally the ratio of mental age (ma) to chronological age (ca) multiplied by 100 IQ = (ma/ca x 100) on contemporary tests, the average performance for a given age is assigned a score of 100

Origins of Intelligence Testing If mental and chronological age are the same, IQ = 100. Most current intellectual tests, no longer measure an IQ. Original formula works for children, not for adults. Today’s intellectual tests compare mental ability score based on test-taker’s performance relative to the average performance of others that are the same age. 2/3 of all people score between 85-115.

Assessing Intelligence Aptitude Test a test designed to predict a person’s future performance (ex. SAT) aptitude is the capacity to learn Achievement Test a test designed to assess what a person has learned (ex. course exam)

Assessing Intelligence Wechsler Adult Intelligence Scale (WAIS) most widely used intelligence test Subtests – (11) verbal performance (nonverbal)

Assessing Intelligence: Sample Items from the WAIS From Thorndike and Hagen, 1977 VERBAL General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution

Assessing Intelligence: Sample Items from the WAIS Subtest of the WAIS-R - Measures abilities to see similarities (Transparency/Analogies)

Assessing Intelligence To be widely accepted, intelligence tests have to be – Standardized Reliable Valid (Stanford-Binet, Wechsler tests met all three.)

Assessing Intelligence Basis for comparing your score to others’ performance – Give test to a representative group of people. When people take test their scores are compared to the sample in #1.

Assessing Intelligence Standardization defining meaningful scores by comparison with the performance of a pretested “standardization group” Normal Curve the symmetrical 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

The Normal Curve (Transparency)

Getting Smarter? Flynn Effect

Flynn Effect Greater test sophistication? Better nutrition? More education? More stimulation in the environment? Less childhood disease? Smaller families and more parental involvement?

Assessing Intelligence Reliability the extent to which a test yields consistent results assessed by consistency of scores on: two halves of the test – split test – odd/even alternate forms of the test retesting Validity the extent to which a test measures or predicts what it is supposed to

Assessing Intelligence Standardized Test Chitlings Test Morris Shoe Size Test – Are these tests – standardized, reliable, valid?

Assessing Intelligence Content Validity the extent to which a test samples the behavior that is of interest driving test that samples driving tasks Criterion behavior (such as college grades) that a test (such as the SAT) is designed to predict the measure used in defining whether the test has predictive validity

Assessing Intelligence Predictive Validity success with which a test predicts the behavior it is designed to predict assessed by computing the correlation between test scores and the criterion behavior also called criterion-related validity

Assessing Intelligence Greater correlation over broad range of body weights 10 9 8 7 6 5 4 3 2 1 Little corre- lation within restricted range Football linemen’s success Body weight in pounds 180 250 290 As the range of data under consideration narrows, its predictive power diminishes

The Dynamics of Intelligence Mental Retardation a condition of limited mental ability indicated by an intelligence score below 70 produces difficulty in adapting to the demands of life varies from mild to profound Down Syndrome retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup

The Dynamics of Intelligence (Transparency)