Chapter 6:

Descriptive Methods

Outline

I. Overview

II. Uses for descriptive methods

A. Descriptive research and causality

1. Can't establish causality

2. However, may suggestcausal hypotheses that could be tested with an experiment

B. Description for description's sake

C. Description for prediction's sake

D. Why do we need science to describe behavior?

1. We need scientific measurement

2. We need systematic, scientific record-keeping

3. We need objective ways to determine relationships

4. We need scientific methods to generalize from experience

E. Conclusions about the need for descriptive research

III. Sources of data.

A. Ex post facto data: Data you have already collected

1. External validity

2. Construct validity

3. Internal validity

4. Conclusions about ex post facto research

B. Archival data

1. Collected and coded data

2. Collected but uncoded data

3. Internal validity

4. Construct validity

5. External validity

6. The limits of aggregate data

7. Conclusions about archival research

C. Observation

1. Types of observational research

2. Problems with observation

a. Effects of the observer on the observed

b. Difficulties in objectively coding behavior

D. Tests

1. External validity

2. Internal validity

3. Conclusions about testing

IV. Describing your data

A. Graph your data

B. Correlation coefficients: When a number may be worth a thousand points

1. The logic behind the Pearson r

2. The coefficient of determination

C. Summary of describing correlational data

V. Making inferences

A. Analyses based on correlation coefficients

B. Analysis not involving correlation coefficients

C. Interpreting significant results

D. Interpreting null results

VI. A look ahead

Summary

Key terms & issues

Exercises