# Chapter 11 pt. 2: Intelligence Assessment. Qualities of A Good Test To be accepted all psychological tests must be: To be accepted all psychological tests.

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Chapter 11 pt. 2: Intelligence Assessment

Qualities of A Good Test To be accepted all psychological tests must be: To be accepted all psychological tests must be: 1. Standardized 2. Reliable 3. Valid

Standardization Standardization: is a two part test development procedure that first establishes test norms by testing a representative sample of individuals who initially took the test, then assures the test is administered and scored correctly for all administrators. Standardization: is a two part test development procedure that first establishes test norms by testing a representative sample of individuals who initially took the test, then assures the test is administered and scored correctly for all administrators. Your scores are compared with the pretested group scores (norms) who took the test. Your scores are compared with the pretested group scores (norms) who took the test. Standardized tests usually follow a normal distribution. Standardized tests usually follow a normal distribution.

Standardized Tests Usually Follow a Normal or Bell Curved Distribution Where Most Scores Occur in the Middle. Ninety-five percent of all people fall within 30 points of 100 Number of scores 55 70 85 100 115 130 145 Wechsler intelligence score Sixty-eight percent of people score within 15 points above or below 100

Understanding Distributions: Variance and Standard Deviation Both variance and standard deviation are measures which tell us how scores differ from one another or how spread out the distribution is. Both variance and standard deviation are measures which tell us how scores differ from one another or how spread out the distribution is. Variance is reported in squared units. Variance is reported in squared units. To get the standard deviation which will be in regular units you just take the square root of the variance. To get the standard deviation which will be in regular units you just take the square root of the variance.

Reliability vs. Validity (DON’T MIX THEM UP) Reliability deals with consistency. Reliability deals with consistency. Asks the question do I always get SIMILAR results each time the test is administered? Asks the question do I always get SIMILAR results each time the test is administered? QUESTION: Would basing intelligence on a man’s arm pit hair color be a reliable measure? Why or Why Not? QUESTION: Would basing intelligence on a man’s arm pit hair color be a reliable measure? Why or Why Not?

Classic Examples of Ways to Check Reliability (Consistency) 1. Test/Retest: same test is administered to the same group on two different occasions and compared. 1. Test/Retest: same test is administered to the same group on two different occasions and compared. 2. Split half: score on one half of test questions is correlated with the score on the other half to see if they are consistent. 2. Split half: score on one half of test questions is correlated with the score on the other half to see if they are consistent. 3. 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 to see if results are consistent. 3. 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 to see if results are consistent.

Reliability vs. Validity (DON’T MIX THEM UP!) Validity deals with accuracy or predictability. Validity deals with accuracy or predictability. Asks the question does the test measure what it is supposed to measure? Asks the question does the test measure what it is supposed to measure? Would using a scale that assessed athletic ability by measuring fingernail length be a valid measure? Why or Why Not? Would using a scale that assessed athletic ability by measuring fingernail length be a valid measure? Why or Why Not?

Types of Validity 1. Content or Face Validity: is a measure of the extent to which the content of the test measures all of the knowledge or skills that are supposed to be included within the domain being tested? 1. Content or Face Validity: is a measure of the extent to which the content of the test measures all of the knowledge or skills that are supposed to be included within the domain being tested? Example: If 45% of the Chapter 11 AP Psych Exam asks you to solve calculus problems it lacks content or face validity. Example: If 45% of the Chapter 11 AP Psych Exam asks you to solve calculus problems it lacks content or face validity. 2. Predictive Validity: The success with which a test predicts the behavior it is supposed to predict. 2. Predictive Validity: The success with which a test predicts the behavior it is supposed to predict. Do high SAT scores correlate with high college grades? Do high SAT scores correlate with high college grades?

Types of Validity 3. Construct Validity: refers to whether or not a scale measures the theorized concept (or construct) it is supposed to. 3. Construct Validity: refers to whether or not a scale measures the theorized concept (or construct) it is supposed to. If an IQ test has construct validity, it would mean the problems truly deal with all the components that make a person intelligent. (Intelligence would be the construct). If an IQ test has construct validity, it would mean the problems truly deal with all the components that make a person intelligent. (Intelligence would be the construct).

Predictive Validity is Based on Criterion Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful. Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful. What would the criterion be for the SAT’s? What would the criterion be for the SAT’s? What would the criterion be for the NFL combine drills? What would the criterion be for the NFL combine drills?

The Flynn Effect Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect). Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect). If standardized with today’s tests, scores 80 years ago would have a average IQ of 76. If standardized with today’s tests, scores 80 years ago would have a average IQ of 76. Possible Causes? Possible Causes?

The Flynn Effect

Low Extreme of Intelligence Mental Retardation: condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life. Mental Retardation: condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life. Caused by genetic disorders, difficulties during childbirth, and women who drink and use drugs while pregnant. Caused by genetic disorders, difficulties during childbirth, and women who drink and use drugs while pregnant.

Low Extreme of Intelligence Down Syndrome: condition of retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup. Down Syndrome: condition of retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup. Many mentally retarded people with Down Syndrome can adapt to disorder and some have earned college degrees with accomodations…nearly all learn how to read. Many mentally retarded people with Down Syndrome can adapt to disorder and some have earned college degrees with accomodations…nearly all learn how to read.

Degrees of Mental Retardation Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life Mild 50-70 85% Most learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate 35-49 10 May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe 20-34 3-4 May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training.

Key Dynamic of Intelligence Creativity: the ability to produce novel and valuable ideas Creativity: the ability to produce novel and valuable ideas components of creativity: components of creativity: expertise expertise imaginative thinking skills imaginative thinking skills venturesome personality venturesome personality intrinsic motivation intrinsic motivation creative environment creative environment

Is Intelligence Genetic or Environmental? Influenced by both, but the most genetically similar have the most similar scores. Influenced by both, but the most genetically similar have the most similar scores. Similarity of intelligence scores (correlation) Identical twins reared together Identical twins reared apart Fraternal twins reared together Siblings reared together Unrelated individuals reared together

Genetic Influences With age, genetic influences become more apparent. With age, genetic influences become more apparent. Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age. Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age. Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability). Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability).

Genetic Influences 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 3 years 16 years Child-parent correlation in verbal ability scores Children and their birth parents Adopted children and their birth parents Adopted children and their adoptive parents

Schooling Effect Grade 6 Grade 5 Grade 4 110 115 120 125 130 135 140 145 150 Age in months 118 115 112 109 106 103 100 97 IQ gains relative to grade 4 baseline

Group Differences in Intelligence Scores Are Probably Mostly Attributed to the Environment Variation within group Difference within group Poor soilFertile soil Seeds

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