Testing IntelligenceTesting Intelligence

ARE YOU OVER-TESTED?ARE YOU OVER-TESTED?

Your age group is the most tested group in Your age group is the most tested group in the history of the United States. the history of the United States.

Types of TestsTypes of Tests

Aptitude TestAptitude Test - predicts your ability to - predicts your ability to learn a new skill. (future performance)learn a new skill. (future performance)

Achievement TestAchievement Test - reflects what you - reflects what you have learned. (current performance)have learned. (current performance)

Wechsler Adult Intelligence Wechsler Adult Intelligence Scale (WAIS)Scale (WAIS)

The most widely used intelligence test The most widely used intelligence test created by David Wechsler.created by David Wechsler.

Contains verbal and performance subtestsContains verbal and performance subtests Look at page 446 in test to see sample Look at page 446 in test to see sample

questions. questions. If scores on verbal and performance are If scores on verbal and performance are

drastically different, it drastically different, it could could indicate a indicate a learning disability. learning disability.

Test Criteria Test Criteria

A PSYCHOLOGICAL TESTS SHOULD A PSYCHOLOGICAL TESTS SHOULD BEBE StandardizedStandardized ReliableReliable ValidValid

StandardizationStandardization StandardizationStandardization – defining meaningful scores – defining meaningful scores

by comparison with the performance of a by comparison with the performance of a standardized groupstandardized group

For a test to be standardized, the condition of For a test to be standardized, the condition of taking the test need to be as similar as possibletaking the test need to be as similar as possible

Results should form a normal curve (bell Results should form a normal curve (bell shaped) with most scores falling in the average shaped) with most scores falling in the average and less score falling in the extremes. and less score falling in the extremes.

A score is given based on how the test-taker’s A score is given based on how the test-taker’s score varies from the mean. score varies from the mean.

The Normal (Bell) CurveThe Normal (Bell) Curve

Standardized test results usually form a Standardized test results usually form a bell-shaped curve (bell-shaped curve (normal curvenormal curve – most – most scores fall near the average and few scores fall near the average and few scores lie at the extremes). REFER TO scores lie at the extremes). REFER TO PAGE 434PAGE 434

The Normal (Bell) Curve and The Normal (Bell) Curve and Standard DeviationStandard Deviation

The Standard Deviation (z score) for the normal curve on the WAIS and other standardized Intelligence tests is always 15. The S.D. is how much scores vary from the mean.

Normal (Bell) Curve andNormal (Bell) Curve and Standard Deviation Standard Deviation

What this means is about 68% of the test takers will score between 15 points lower than the mean and 15 points higher than the mean because 68% is ALWAYS 1z (z=standard deviation). Q What are these scores on the WAIS?. The other 32% that take a test score outside of that.

Standard DeviationStandard Deviation

About 95% of test takers will score between 30 pts. lower than the mean and 30 pts. higher than the mean because about 95% is ALWAYS 2z (standard deviation). Q What are these scores on the WAIS?

The Bell CurveThe Bell Curve

If the mean on a test is 80 and the standard If the mean on a test is 80 and the standard deviation (1z score) is 5deviation (1z score) is 5

1. 68% of the test takers scored between a 1. 68% of the test takers scored between a ___ and ____?___ and ____?

2. What percent of the test takers scored 2. What percent of the test takers scored between a 70 and a 90?between a 70 and a 90?

3. If I scored 1 standard deviation above the 3. If I scored 1 standard deviation above the mean what was my score?mean what was my score?

4. If I scored 3 standard deviations below 4. If I scored 3 standard deviations below the mean what was my score?the mean what was my score?

If the mean on a test is 80 and the standard If the mean on a test is 80 and the standard deviation ((1)z score) is 5deviation ((1)z score) is 5

What percent of test takers scored above What percent of test takers scored above a 90?a 90?

If I scored a 70 what is my z score?If I scored a 70 what is my z score? On the Normal curve for a standardized On the Normal curve for a standardized

intelligence test (ex.- the WAIS) what intelligence test (ex.- the WAIS) what percent of the population scores above an percent of the population scores above an 85?85?

What percent scored above a 115?What percent scored above a 115?

NC Teacher refuses to give NC Teacher refuses to give standardized test.standardized test.

Teacher says no to testing - YouTube

Test to Measure Optimism and Test to Measure Optimism and Pessimism in PersonalityPessimism in Personality

1. Prefer A. Hamburgers B. Hot Dogs1. Prefer A. Hamburgers B. Hot Dogs 2. What kinds of grades do you tend to 2. What kinds of grades do you tend to

get? A. Good B. Badget? A. Good B. Bad 3. Which do you prefer? A. Talking on 3. Which do you prefer? A. Talking on

telephone B. Going to Moviestelephone B. Going to Movies 4. Which color do you like best? A Red B 4. Which color do you like best? A Red B

BlueBlue

Validity Validity ValidityValidity – the extent to which a test – the extent to which a test

measures or predicts what it is supposed measures or predicts what it is supposed to, the to, the accuracyaccuracy of the test. of the test.

Was the Optimism test valid?Was the Optimism test valid? Can you make it valid?Can you make it valid? (glass, thoughts on rainy days)(glass, thoughts on rainy days)

Types of Validity Types of Validity Content validityContent validity – How well does the test measure – How well does the test measure

the entire range of material it is supposed to test?the entire range of material it is supposed to test? Ex. of low content validity – spending 5 minutes on Ex. of low content validity – spending 5 minutes on

depression in class and asking 30 questions on depression in class and asking 30 questions on depression for the Ch. 16 test. depression for the Ch. 16 test.

Predictive validity Predictive validity – the success of the test in – the success of the test in predicting the behavior it is supposed to predict. predicting the behavior it is supposed to predict. Ex. SAT is said to predict your performance in college. It Ex. SAT is said to predict your performance in college. It

actually only predicts freshman year success. High actually only predicts freshman year success. High school grades much better predictor.school grades much better predictor.

CriterionCriterion – the behavior a test is supposed to measure. – the behavior a test is supposed to measure.

ReliabilityReliability

ReliabilityReliability – the extent to which a test – the extent to which a test yields consistent results, yields consistent results, consistencyconsistency of of the test.the test.

Measuring ReliabilityMeasuring Reliability

Equivalent –form reliabilityEquivalent –form reliability – correlation – correlation between performance on different forms of the between performance on different forms of the test. Q State check for on EOC’s?test. Q State check for on EOC’s?

Test-retest reliabilityTest-retest reliability – correlation between – correlation between one’s score of the first administration of the test one’s score of the first administration of the test and the score of the second administration of and the score of the second administration of the test. (Ex. SAT’s)the test. (Ex. SAT’s)

Split-half reliabilitySplit-half reliability – randomly dividing the – randomly dividing the tests into two parts and correlating one’s tests into two parts and correlating one’s performance on the two parts. performance on the two parts.

The closer the correlation is to +1 … the more The closer the correlation is to +1 … the more reliable the test isreliable the test is Stanford-Binet and the WAIS have a reliability of +.9Stanford-Binet and the WAIS have a reliability of +.9

Testing Mental Retardation Testing Mental Retardation Those whose IQ score falls below 70 are labeled Those whose IQ score falls below 70 are labeled

as having mental retardation. (pg. 452)as having mental retardation. (pg. 452) Criteria for diagnosis:Criteria for diagnosis:

Low test scoreLow test score Difficulty adapting to the normal demands for Difficulty adapting to the normal demands for

independent livingindependent living Mental retardation affects 1% of the population. Mental retardation affects 1% of the population. Mental retardation affects males more than Mental retardation affects males more than

femalesfemales