EXERCISE 6

PSYCHOLOGICAL MEASUREMENT (806)

OCTOBER 27, 1998

DUE NOVEMBER 3

 
DIRECTION -- Use the information on the attached sheet to answer the following questions.

 

1. Compute a principal component analysis using the default values from SPSSX or SAS (Note, use the factor analysis program, not the principal component program in SAS). You need to conduct a rotation.

 

2. How many factors does the program suggest you have and why?

 

3. Based on the results from question 1 and 2, rerun the analysis forcing a reduced number of factors. How does this help you, if it does, to understand the factors?

 

4. Interpret the findings and tell me how this helps to understand the correlation's you started with in the table.

 

Exercise 6:

INTERCORRELATIONS OF NINE AIR FORCE TESTS, THEIR MEANS AND STANDARD DEVIATIONS*

TEST

1

2

3

4

5

6

7

8

9

1

 

.38

.55

.06

-.04

.05

.07

.05

.08

2

.38

 

.36

.40

.28

.40

.11

.15

.13

3

.55

.36

 

.10

.01

.18

.13

.12

.10

4

.06

.40

.10

 

.32

.60

.04

.06

.13

5

-.04

.28

.01

.32

 

.35

.08

.13

.11

6

.05

.40

.18

.60

.35

 

.01

.06

.07

7

.07

.11

.13

.04

.08

.01

 

.45

.32

8

.05

.15

.12

.06

.13

.06

.45

 

.32

9

.08

.13

.10

.13

.11

.07

.32

.32

 

M

48.1

18.5

19.3

7.3

27.2

14.5

27.8

31.3

15.5

s

19.9

7.0

11.9

3.7

6.7

8.3

5.6

7.5

5.1

 

*The statistics given in the table did not arise from a single administration of the tests to the same sample. They are selected as being typical, however, from a number of different sources (25). The population was composed of aviation students as they took classifications test during World War II. The N's varied from about 400 to about 8,000 for the intercorrelations.

Nature of the tests:

      1. AAF Vocabulary -- a multiple choice synonym test.

      2. Technical Vocabulary (Pilot) -- composed of terms such as an aircraft pilot learns.

      3. Reading Comprehension -- based on short paragraphs such as a pilot has to read in technical manuals.

      4. Tool Functions -- on knowledge of the uses of common tools.

      5. Biographical Data Blank (Pilot) -- containing items about past experiences.

      6. Mechanical Information -- mostly about knowledge of automotive equipment and repairs.

      7. Spatial Orientation I -- requires rapid matching of aerial photographs.

      8. Speed of Identification -- requires rapid matching of pictures of airplanes.

      9. Pattern Assembly -- a paper-form board type of test.

 

For more details concerning these tests, see Guilford and Lacey (25).