1. Unit 11: Testing and Individual Differences
AP Psychology
Mr. Fuller

2. Measuring Individual Differences
Psychology relies heavily on testing individuals, it is part of the foundation for psychological analysis. To be effective, however, strict guidelines must be followed.
Validity: Does the test actually measure what we say it does/what we want it to?
Ex. Reading on a math test
Face validity: Does the test look like it tests what it is supposed to test?
Content validity: Each part of the test is representative of the larger body of knowledge.

3. Measuring Individual Differences
Criterion Validity: The behavior (such as college grades) that a test (such as the SAT) is designed to predict
Predictive Validity: The success with which a test predicts the behavior it is designed to predict.

4. Assessing Intelligence
Greater correlation
over broad range
of body weights 10 9 8 7 6 5 4 3 2 1
Little corre-
lation within
restricted
range
Football linemen’s
success
Body weight in pounds
As the range of data under consideration narrows, its predictive power diminishes

5. Measuring Individual Differences
The second part of a credible test is reliability.
Reliability: A test yields the same results over time
Test-Retest or Split-Half Reliability
Reliable, but not valid
Not reliable, not valid
Reliable and valid

6. Creating Validity and Reliability
The most efficient way to create validity and reliability is to use a standardized test.
In the most basic sense, a standardized test means:
The administration and scoring is the same for each test
The results of the test can be used to draw a conclusion about the test takers in regard to the objectives of the test.
Ex. AP test, S.A.T.

7. Judging Normal
A “normal curve” is applied to test to determine establish “norms.” When a statistically significant sample of the population has been tested, strong conclusions can be drawn.
A normal range for IQ scores is Scores below 70 indicate mental retardation while scores above 130 are considered gifted.

8. Normal Distribution of IQ Scores

9. Degrees of Mental Retardation

10. Types of Tests There are two main types of tests:
Objective Tests: Tests that have one set answer, that can be scored easily by machine
Ex. Multiple choice
Subjective Tests: Tests in which individuals are given ambiguous figures or an open ended question which requires some interpretation and analysis.
Ex. FRQs
Inter-rater reliability

11. Sample Subjective Test
The Rorschach Inkblot Test is one of the most widely known, and inaccurate subjective tests.
The following slides are real inkblots from the test that was, at one time, a widely used test. Today, it has lost much, if not all of its credibility in determining intelligence or mental illness.

18. Intelligence Testing
A term that is used frequently, but often misunderstood is “intelligence.” What exactly is intelligence?
Many people disagree about what exactly intelligence is, but most do agree that it is:
Relative: defined in relation to the same abilities in a comparison group (usually age)
Hypothetically constructed: it is unobservable, but instead inferred from behavior

19. Testing IQ
IQ (intelligence quotient) became a popular way to classify people in the early 1900s when two French psychologists (Alfred Binet and Theodore Simon) developed a test to identify those students who were gifted, and those who needed extra help.

20. Binet-SimonTest The test had four important distinctions:
Scores were interpreted at their current performance
Used to identify students in need of help, not label them or categorize them
Emphasized that training and opportunity could affect intelligence
Was empirically constructed
Scoring the test was done by calculating the mental age (MA) and the chronological age (CA).
MA= The average age at which normal individuals achieve a particular score
CA= The number of years since an individuals birth

21. Coming to America
The idea of IQ testing became popular in America for three reasons:
A huge increase in immigration
New laws requiring universal education
Military assessing new recruits for WWI
It created an inexpensive and objective way to separate those could benefit from education or military leadership training and those who needed assistance.

22. Downside of IQ Testing
Despite its utility, IQ testing had a big downside. Tests ended up reinforcing prevailing prejudices about race and gender.
Ignored was the fact that environmental disadvantages limit the full development of people’s intellectual abilities.
Same problem of NCLB!!!

23. Stanford-Binet Intelligence Scale
When the Binet test was adopted by a Stanford professor, he changed the equation to make intelligence scores into non-decimal numbers. This now became known as the Intelligence Quotient (IQ).
=IQ

24. Components of Intelligence
Savant Syndrome: Individuals with remarkable, but rare talent, even though they are mentally deficient in other areas.
Ex. Dustin Hoffman in Rain Man

25. Theories of Intelligence
Spearman’s g Factor: Charles Spearman thought intelligence was a general factor behind all of our mental ability.
Catell’s Fluid and Crystallized Intelligence
The g factor

26. Theories of Intelligence
Howard Gardner believed that IQ scores measured only a limited range of human mental abilities. He argued we have seven separate mental abilities he calls the multiple intelligences.
Linguistic intelligence ("word smart"):
Logical-mathematical intelligence ("number/reasoning smart")
Spatial intelligence ("picture smart")
Bodily-Kinesthetic intelligence ("body smart")
Musical intelligence ("music smart")
Interpersonal intelligence ("people smart")
Intrapersonal intelligence ("self smart")