chapter 11 testing and individual differences. validity and reliability validity: a property...

Chapter 11

Testing and Individual Differences

Validity and Reliability Validity: A property exhibited by a test that

measures what it is supposed to measureFace validityContent validity

Item analysis

Criterion validity Reliability: A property exhibited by a test that

yields the same results over timeTest-retest reliabilityAlternate form reliabilitySplit-half reliability

Standardization and Norms

Scientists use statistics to establish a normal curve

This curve can be used to describe most phenomena (IQ for example)

Normal range: Scores falling near the middle of a normal distribution

The Normal Distribution of IQ Scores

Types of Tests Objective tests: can be scored easily by

machine Subjective tests: individuals are given an

ambiguous figure or an open-ended situation and asked to describe what they see or finish a story

Inter-rater reliability: measures how similarly two different test scorers would score a test

Intelligence: includes acquiring knowledge, ability to reason, solve problems

How is IntelligenceMeasured?

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

How is IntelligenceMeasured?

Binet-Simon Test – compared a child’s mental age to his or her chronological age Current performance, not measure of innate intelligence Identify those that need help, not to label Training & opportunity could affect intelligence Empirical – observed child’s performance

U.S. - widespread for the assessment of Army recruits, immigrants, and schoolchildren

The Stanford-Binet: standardized its administrations and its age-level norms; most respected

How is IntelligenceMeasured?

Intelligence quotient: Numerical score on an intelligence test, dividing mental age by chronological age and multiplying by 100 (IQ = MA/CA x 100)

Problems: Adults appeared to be mentally retarded!!! Original IQ has been abandoned in favor of a mental ability

score based on performance relative to the average performance of others the same age.

Achievement test – measures knowledge of a subject Aptitude test – measures capacity for learning Wechsler (AIS) and (ISC) – less on formal schooling

The Normal Distribution of IQ Scores

The Exceptional Child Mental retardation: Often conceived as

representing the lower 2% of the IQ rangeLower than IQ of 70“significant sub-average intellectual functioning”Limitations in at least 2 areas

CausesDown Syndrome – geneticFetal Alcohol Syndrome - environmentalPhenylketonuria (PKU) – caught earlydiet

The Exceptional Child

Giftedness: Often conceived as representing the upper 2% of the IQ rangeHigher than IQ of 130Terman (1921) - 1528 kids w/ IQ 135+

High correlation between IQ and academic performance

Healthy, happy, well-adjusted, successful

What Are the Componentsof 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

Psychometric Theories of Intelligence

Psychometrics: mental measurements g Factor: General ability as the main factor

underlying all intelligent mental activity (Spearman)

Crystallized intelligence: Knowledge a person has acquired, plus the ability to access that knowledge

Increases with age until around 75 (Cattell)

Fluid intelligence: The ability to see complex relationships and solve problems

Decreases slowly with age – esp 75+ (Cattell)

What Are the Components of Intelligence?

Evidence against the g factor… Savant syndrome: Found in individuals who

have a remarkable talent even though they are mentally slow in other domains

Kim Peek – Rain Man Stephen Wiltshire http://www.youtube.com/watch?v=a8YXZTlwTAU

Cognitive Theories of Intelligence

Beyond emphasis on vocab, logic, problem solving & other skills to predict school success.

Cognitive processes that contribute to success in many areas of life.Sternberg’s Triarchic TheoryGardner’s Multiple Intelligences

Sternberg’s Triarchic Theory

Practical Intelligence: ability to cope with the environment; aka street smarts

Analytical Intelligence: ability to analyze problems and find correct answers; ability measured by most IQ tests; aka logical reasoning

Creative Intelligence: form of intelligence that helps people see new relationships among concepts

Cognitive TheoriesGardner’s Multiple Intelligences

LinguisticLinguistic

Logical-MathematicalLogical-Mathematical

SpatialSpatial

MusicalMusical

Bodily-KinestheticBodily-Kinesthetic

InterpersonalInterpersonal

IntrapersonalIntrapersonal

Gardner’s Multiple IntelligencesLinguisticLinguistic

Logical-Mathematical

Spatial

Musical

Bodily-Kinesthetic

Interpersonal

Intrapersonal

Often measured on IQ tests with reading comprehension and vocabulary tests

Gardner’s Multiple IntelligencesLinguistic

Logical-MathematicalLogical-Mathematical

Spatial

Musical

Bodily-Kinesthetic

Interpersonal

Intrapersonal

Often measured on IQ tests with analogies, math problems and logic problems

Gardner’s Multiple IntelligencesLinguistic

Logical-Mathematical

SpatialSpatial

Musical

Bodily-Kinesthetic

Interpersonal

Intrapersonal

Ability to form mental images of objects and think about their relationships in space

Gardner’s Multiple IntelligencesLinguistic

Logical-Mathematical

Spatial

MusicalMusical

Bodily-Kinesthetic

Interpersonal

Intrapersonal

Ability to perceive and create patterns of rhythms and pitches

Gardner’s Multiple IntelligencesLinguistic

Logical-Mathematical

Spatial

Musical

Bodily-KinestheticBodily-Kinesthetic

Interpersonal

Intrapersonal

Ability for controlled movement and coordination

Gardner’s Multiple IntelligencesLinguistic

Logical-Mathematical

Spatial

Musical

Bodily-Kinesthetic

InterpersonalInterpersonal

Intrapersonal

Ability to understand other people’s emotions, motives and actions

Gardner’s Multiple IntelligencesLinguistic

Logical-Mathematical

Spatial

Musical

Bodily-Kinesthetic

Interpersonal

IntrapersonalIntrapersonal

Ability to know oneself and to develop a sense of identity

Gardner’s Three New Intelligences

Naturalistic intelligence Spiritual intelligence Existential intelligence

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

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 asHealthEconomicsEducation

Heritability and Group Differences

Heritability: Amount of trait variation within a group, raised under the same conditions, that can be attributed to genetic differences

Heritability says nothing about between-group differences

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