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1.18.2011 DO NOW

1.18.2011 DO NOW. What is an IQ test? What do you think it is measuring?. Unit 6: Testing & Individual Differences. Key Ideas:. Standardization and norms Reliability and Validity Types of tests Ethics and standards in testing Intelligence Intelligence testing Kinds of intelligence

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1.18.2011 DO NOW

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  1. 1.18.2011 DO NOW • What is an IQ test? • What do you think it is measuring?

  2. Unit 6: Testing & Individual Differences

  3. Key Ideas: • Standardization and norms • Reliability and Validity • Types of tests • Ethics and standards in testing • Intelligence • Intelligence testing • Kinds of intelligence • Heredity/environment and intelligence • Human diversity

  4. Standardization & Norms • Psychometricians (measurement psychologists): focus on methods for acquiring and analyzing psychological data. • They measure mental traits, abilities, and processes.

  5. Standardization & Norms • Constructs: hypothetical abstractions related to behavior and defined by groups of objects or events. • A good test is standardized, reliable, and valid.

  6. Standardization & Norms • Standardization: two-part test development procedure • first establishes test norms from the test results of the large representative sample • second assures that the test is both administered and scored uniformly for all test takers.

  7. Standardization & Norms • Norms: standards used to compare scores of test takers. • e.g. the mean score of the SAT is 500 and the standard deviation is 100. • the mean score for an IQ test is 100 and the standard deviation is 15.

  8. Reliability & Validity • Reliability: consistency of results over time (repeatability). • Methods of measurement include test-retest, split-half, alternate form.

  9. Reliability & Validity • Test-retest: the same exam is administered to the same group on two different occasions and the scores are compared. • The closer the correlation coefficient is to 1.0, the more reliable the test. • The second test may be better than the first because the test-takers are already familiar with the questions.

  10. Reliability & Validity • Split-half: the score on one half of the test questions is correlated with the score on the other half of the questions to see if they are consistent.

  11. Reliability & Validity • Alternate form/Equivalent form: two different versions of a test on the same material are given to the same test takers, and the scores are correlated. • e.g. If a SAT given on Saturday is different from a SAT given on Sunday, and someone took both and they have high reliability, they should get the same scores on both tests.

  12. Reliability & Validity • Interrater reliability: the extent to which two or more scorers evaluate the responses in the same way.

  13. Reliability & Validity • Validity: test measures what it is supposed to measure. • Methods of measurement include face, content, predictive, and construct. • face validity: does it seem to measure what it’s supposed to be measuring. • e.g. giving math problems to test math ability.

  14. Reliability & Validity • Content validity: the content of the test measures all of the knowledge or skills that are supposed to be included within the domain being tested, according to expert judges. • Criterion related validity: a measure of the extent to which a test’s results correlate with other accepted measures of what is being tested.

  15. Reliability & Validity • Predictive validity: a measure of the extent to which the test accurately forecasts a specific future result. • e.g. the ACT is designed to predict college preparedness. • High scores on the ACT should predict high grades in one’s first year of college.

  16. Reliability & Validity • Construct validity: the extent to which the test actually measures the hypothetical construct or behavior it is designed to assess. • Does a clinical test for schizophrenia successfully discriminates people with schizophrenia from other subjects taking the same test.

  17. 1.19.2011 DO NOW • Briefly describe one type of reliability and one type of validity. • Reading notes (p. 430 – 467, Mod. 31-33 DUE Friday, Jan. 21st).

  18. Types of Tests • Performance tests: test taker knows how to respond to questions and tries to succeed. • e.g. ACT, AP exams • Speed tests: large number of relatively easy items in limited test periods. • Power tests: items of varying difficulty with adequate test period.

  19. Types of Tests • Aptitude tests: assess person’s capacity to learn, predict future performance (e.g. ACT). • Achievement tests: assess what a person has already learned (e.g. AP exam).

  20. Types of Tests • Group tests: test many people at one time. • Test taker works alone • Cheaper • More objective • Individualized tests: interaction of one examiner with one test taker. • Expensive • Subjective grading

  21. Ethics and Standards in Testing • APA and other guidelines create standards to: • promote best interests of client • guard against misuse • respect client’s right to know results

  22. Ethics and Standards in Testing • APA and other guidelines create standards to: • safeguard dignity. • Informed consent is needed. • Confidentiality is guaranteed.

  23. Intelligence & Intelligence Testing • Reification: construct treated as a concrete, tangible object. • Intelligence: aggregate or global capacity to act purposefully, to think rationally, and to deal effectively with the environment.

  24. Intelligence & Intelligence Testing • Stanford-Binet intelligence test: an individual intelligence quotient (IQ) test with IQ calculated using the ratio formula: mental age/chronological age x 100. • Now, IQ is based on deviation from the mean for children and for adults. • Five ability areas are assessed both verbally and nonverbally.

  25. Intelligence & Intelligence Testing • So, if someone’s mental age is 8, and their chronological age is 8, what is their IQ? • Mental age of 15, chronological age of 30. • Mental age of 20, chronological age of 10.

  26. Intelligence & Intelligence Testing

  27. Intelligence & Intelligence Testing • Wechsler intelligence tests: three age-based individual IQ tests: WPPSI (Wechsler Preschool and Primary Scale of Intelligence), WISC (Wechsler Intelligence Scale for Children), WAIS (Wechsler Adult Intelligence Scale).

  28. Intelligence & Intelligence Testing • Two scores: verbal and performance • Difference between the two is helpful for identifying learning disabilities • Deviation IQ score – mean/median/mode = 100; 15 point standard deviation • Good for extremes of gifted and mentally retarded or cognitively disabled.

  29. Intelligence & Intelligence Testing • Degrees of cognitive disability (mental retardation): • Mild – IQ 50-70: can self-care, hold job, may live independently, form social relationships. • Moderate – IQ 35-49: may self-care, hold menial job, function in group home.

  30. Intelligence & Intelligence Testing • Degrees of cognitive disability (mental retardation): • Severe – IQ 20-34: limited language and limited self-care, lack social skills, require care. • Profound – IQ under 20: require complete custodial care.

  31. Intelligence & Intelligence Testing • Factor analysis: a statistical procedure that identifies common factors among groups of items by determining which variables have a high degree of correlation. • Charles Spearman used factor analysis to identify g: general factor underlying all intelligence. • s: less important specialized abilities

  32. 1.20.2011 DO NOW • Briefly describe one of the types of tests discussed yesterday AND GIVE AN EXAMPLE. • Reading notes (p. 430 – 467, Mod. 31-33 DUE Friday, Jan. 21st). • Online IQ test: www.intelligencetest.com/

  33. Intelligence & Intelligence Testing • Thurstone’s primary mental abilities – seven distinct intelligence factors.

  34. Intelligence & Intelligence Testing • John Horn and Raymond Cattell identified two intelligence factors: • Fluid intelligence: those cognitive abilities requiring speed or rapid learning that tend to diminish with adult aging. • e.g. math and science skills

  35. Intelligence & Intelligence Testing • Crystallized intelligence: learned knowledge and skills, such as vocabulary, which tend to increase with age. • e.g. language and writing skills

  36. Intelligence & Intelligence Testing • Multiple intelligences: Howard Gardner’s theory that people process information differently and intelligence is composed of many different factors, including at least eight intelligences: logical-mathematical, verbal-linguistic, spatial, bodily-kinesthetic, musical, interpersonal, intrapersonal, and naturalistic.

  37. Intelligence & Intelligence Testing • Emotional intelligence: Peter Salovey and John Mayer’s construct defined as the ability to perceive, express, understand, and regulate emotions. • Similar to Gardner’s interpersonal and intrapersonal intelligences.

  38. Intelligence & Intelligence Testing • Triarchic theory of intelligence: Robert Sternberg’s idea of three separate and testable intelligences: analytical (facts), practical (“street smarts”), and creative (seeing multiple solutions).

  39. Intelligence & Intelligence Testing • Creativity: the ability to generate ideas and solutions that are original, novel, and useful is not usually measured by intelligence tests. • Threshold theory: a certain level of intelligence is necessary, but not sufficient for creative work.

  40. Heredity/Environment & Intelligence • Both nature and nurture contribute to intelligence. • Down syndrome is primarily hereditary. • fetal alcohol syndrome (FAS) is primarily environmental. • Phenylketonuria (PKU) results form both nature and nurture.

  41. Heredity/Environment & Intelligence • Cultural-familial retardation: retardation attributed to sociocultural deprivation. • In twin studies, correlation of IQs of identical twins was much higher than fraternal twins or siblings (favoring nature).

  42. Heredity/Environment & Intelligence • Flynn effect: steady increase in performance on IQ tests over the last 80 years, possibly resulting from better nutrition, educational opportunities, and health care (favoring nurture). • Heritability: the proportion of variation among individuals in a population that results from genetic causes. • Heritability for intelligence is 50 to 75%.

  43. Human Diversity • Within-group differences: range of scores for variables being measured for a group of individuals. • Between-group differences: usually the difference between means of two groups of individuals for a common variable.

  44. Human Diversity • Stereotype threat: Claude Steele’s concept that anxiety influences achievement of members of a group concerned that their performance on a test will confirm a negative stereotype. • This may account for lower scores of blacks on intelligence tests or girls on math tests.

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