2 Assessing Intelligence One-Minute Intelligence Test
3 Origins of Intelligence Testing Alfred Binet – French Psychologistdeveloped intelligence test when schools needed a way to objectively identify students with special needsbelieved that all children follow same path of development, some develop more rapidly
4 Origins of Intelligence Testing Mental Agea measure of intelligence test performance devised by Binetchronological age that most typically corresponds to a given level of performancechild who does as well as the average 8-year-old is said to have a mental age of 8
5 Origins of Intelligence Testing Stanford-Binetthe widely used American revision of Binet’s original intelligence testrevised by Terman at Stanford Universityextended range to include adultsDeveloped test to evaluate immigrants and WWI army recruits – cultural bias
6 Origins of Intelligence Testing Intelligence Quotient (IQ)defined originally the ratio of mental age (ma) to chronological age (ca) multiplied by 100IQ = (ma/ca x 100)on contemporary tests, the average performance for a given age is assigned a score of 100
7 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
8 Assessing Intelligence Aptitude Testa test designed to predict a person’s future performance (ex. SAT)aptitude is the capacity to learnAchievement Testa test designed to assess what a person has learned (ex. course exam)
10 Assessing Intelligence: Sample Items from the WAIS From Thorndike and Hagen, 1977VERBALGeneral InformationSimilaritiesArithmetic ReasoningVocabularyComprehensionDigit SpanPERFORMANCEPicture CompletionPicture ArrangementBlock DesignObject AssemblyDigit-Symbol Substitution
11 Assessing Intelligence: Sample Items from the WAIS Subtest of the WAIS-R -Measures abilities to see similarities(Transparency/Analogies)
12 Assessing Intelligence To be widely accepted, intelligence tests have to be –StandardizedReliableValid(Stanford-Binet, Wechsler tests met all three.)
13 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.
14 Assessing Intelligence Standardizationdefining meaningful scores by comparison with the performance of a pretested “standardization group”Normal Curvethe symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributesmost scores fall near the average, and fewer and fewer scores lie near the extremes
17 Flynn Effect Greater test sophistication? Better nutrition? More education?More stimulation in the environment?Less childhood disease?Smaller families and more parental involvement?
18 Assessing Intelligence Reliabilitythe extent to which a test yields consistent resultsassessed by consistency of scores on:two halves of the test – split test – odd/evenalternate forms of the testretestingValiditythe extent to which a test measures or predicts what it is supposed to
19 Assessing Intelligence Standardized TestChitlings TestMorris Shoe Size Test –Are these tests – standardized, reliable, valid?
20 Assessing Intelligence Content Validitythe extent to which a test samples the behavior that is of interestdriving test that samples driving tasksCriterionbehavior (such as college grades) that a test (such as the SAT) is designed to predictthe measure used in defining whether the test has predictive validity
21 Assessing Intelligence Predictive Validitysuccess with which a test predicts the behavior it is designed to predictassessed by computing the correlation between test scores and the criterion behavioralso called criterion-related validity
22 Assessing Intelligence Greater correlationover broad rangeof body weights10987654321Little corre-lation withinrestrictedrangeFootball linemen’ssuccessBody weight in poundsAs the range of data under consideration narrows, its predictive power diminishes
23 The Dynamics of Intelligence Mental Retardationa condition of limited mental abilityindicated by an intelligence score below 70produces difficulty in adapting to the demands of lifevaries from mild to profoundDown Syndromeretardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup