1. Testing and Individual Differences
Chapter 11
Testing and Individual Differences
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2. How Do We Measure Individual Differences?
Measuring individual differences is an essential component of psychology, but strict guidelines and ethical standards must be followed to ensure results and conclusions are valid and appropriate.
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3. Validity and Reliability
Validity – A property exhibited by a test that measures what it purports to measure.
Face validity
Content validity
Criterion validity
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Validity
Face validity
Measures whether a test looks like it tests what it is supposed to test.
Content validity
Each item is representative of the larger body of knowledge about the subject that the test covers.
Criterion validity
Accurately measures performance of the test taker against a specific learning goal.
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5. Validity and Reliability
Reliability – A property exhibited by a test that yields the same results over time.
Test-retest reliability
Split-half reliability
Inter-rater reliability
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Reliability
Test-retest reliability
People get about the same scores when they take the test more than once.
Split-half reliability
A test is split into 2 parts and an individual’s scores on both halves are compared.
Inter-rater reliability
A measure of how similarly two different test scorers would score a test.
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7. Standardization and Norms
Normal range Scores falling near the middle of a normal distribution.
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Types of Tests
Objective tests can be scored easily by machine.
In subjective tests, individuals are given an ambiguous figure or an open-ended situation and asked to describe what they see or finish a story.
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9. Ethics and Standards in Testing
Ethical concerns related to testing involve:
The confidentiality of the test results
How to report the results
How to use the test to compare individuals
Ethics and Standards in Testing
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10. How is Intelligence Measured?
Intelligence testing has a history of controversy, but most psychologists now view intelligence as a normally distributed trait that can be measured by performance on a variety of tasks.
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11. How is Intelligence Measured?
Intelligence quotient (IQ) – A numerical score on an intelligence test, originally computed by dividing a person’s mental age by chronological age and multiplying by 100.
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12. The Normal Distribution of IQ Scores
Many
Number of Persons
Normal Range
Few 10 20 30 40 50 60 70 80 90
110
120
130
140
150
160
170
180
190
200
100 IQ
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How to Calculate IQ
IQ = x 100
Mental Age
Chronological Age
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14. How is Intelligence Measured?
Binet-Simon Test calculated a child’s mental age and compared it to his or her chronological age.
In America, testing became widespread for the assessment of Army recruits, immigrants, and school children.
The Stanford-Binet Intelligence Scale is the most respected of the new American tests of intelligence.
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15. How is Intelligence Measured?
Wechsler tests
Measure a variety of different skills (vocab, verbal comprehension, arithmetic ability, similarities, block design, etc.)
WAIS – Wechsler Adult Intelligence Scale
WISC – Wechsler Intelligence Scale for Children
WPPSI – Wechsler Preschool and Primary Scale of Intelligence
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16. What Are the Components of Intelligence?
Some psychologists believe that the essence of intelligence is a single, general factor, while others believe intelligence is best described as a collection of distinct abilities.
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17. Theories of Intelligence
Charles Spearman
g Factor
A general ability, proposed by Spearman as the main factor underlying all intelligent mental activity.
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18. Theories of Intelligence
Raymond Cattell
Crystallized intelligence – The knowledge a person has acquired, plus the ability to access that knowledge.
Fluid intelligence – The ability to see complex relationships and solve problems.
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19. Robert Sternberg’s Triarchic Theory
Practical Intelligence
Analytical Intelligence
Creative Intelligence
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20. Sternberg’s Triarchic Theory
Practical Intelligence
Ability to cope with the environment; “street smarts”
Analytical Intelligence
Creative Intelligence
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21. Sternberg’s Triarchic Theory
Practical Intelligence
Ability to analyze problems and find correct answers; ability measured by most IQ tests
Analytical Intelligence
also called logical reasoning
Creative Intelligence
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22. Sternberg’s Triarchic Theory
Practical Intelligence
Form of intelligence that helps people see new relationships among concepts; involves insight and creativity
Analytical Intelligence
Creative Intelligence
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23. Howard Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Spatial
Musical
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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24. Gardner’s Multiple Intelligences
Linguistic
Often measured on IQ tests with reading comprehension and vocabulary tests
Logical-Mathematical
Spatial
Musical
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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25. Gardner’s Multiple Intelligences
Linguistic
Often measured on IQ tests with analogies, math problems and logic problems
Logical-Mathematical
Spatial
Musical
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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26. Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Ability to form mental images of objects and think about their relationships in space
Spatial
Musical
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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27. Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Spatial
Ability to perceive and create patterns of rhythms and pitches
Musical
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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28. Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Spatial
Musical
Ability for controlled movement and coordination
Bodily-Kinesthetic
Interpersonal
Intrapersonal
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29. Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Spatial
Musical
Bodily-Kinesthetic
Ability to understand other people’s emotions, motives and actions
Interpersonal
Intrapersonal
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30. Gardner’s Multiple Intelligences
Linguistic
Logical-Mathematical
Spatial
Musical
Bodily-Kinesthetic
Ability to know oneself and to develop a sense of identity
Interpersonal
Intrapersonal
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31. Gardner’s Three New Intelligences
Naturalistic intelligence
- Allows people to classify things as members of diverse groups.
Spiritual intelligence
- The ability to think in abstract spiritual terms and to put oneself in a spiritual frame of mind.
Existential intelligence
- Permits individuals to think about the purpose of existence and the meaning of things like death and love.
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32. How Do Psychologists Explain IQ Differences Among Groups?
While most psychologists agree that both heredity and environment affect intelligence, they disagree on the source of IQ differences among racial and social groups.
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33. How Do Psychologists Explain IQ Differences Among Groups?
Hereditarian arguments maintain that intelligence is substantially influenced by genetics.
Environmental approaches argue that intelligence can be dramatically shaped by influences such as:
Health
Economics
Education
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34. Heritability and Group Differences
Heritability – Amount of trait variation within a group, raised under the same conditions, that can be attributed to genetic differences.
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35. Heritability and Group Differences
Research with twins and adopted children shows genetic influences on a wide range of attributes, including intelligence.
Research has also shown that racial and class differences in IQ scores can be eliminated by environmental changes.
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End of Chapter 11
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