CONTENTS

Table of Contents
Introduction

1. Descriptive Statistics in Evaluation
2. Subgroup Analysis
3. Variable - Are They Related?
4. Correlation
5. The t-Test of Difference Between Means

Supplements
Resources
Glossary

Wading Through the Data Swamp:
Program Evaluation 201

What Did Jack Learn About His Program From These Analyses?

After looking over the excerpt from the evaluator's report, Jack was very confused and was under the impression that his program was a failure. The report was very vague and seemed to highlight the negative results. Of course, Jack did not know what to look for.

Even though the report was very vague, it still included very important information such as the statistically significant difference found between the participant and comparison groups regarding alcohol use. But how was Jack to know that this was a good thing? The evaluator should have included an explanation for each statistical finding.

If the evaluator had included more information in the preliminary report, Jack would have understood that the participants in his program are less likely to use alcohol than those in the comparison group at posttest. This is a huge success that could have been overlooked.

Jack just learned two important things: After participating in his program:

1. Fewer kids used alcohol relative to the comparison group at posttest.
2. The kids' marijuana use was unchanged relative to the comparison group at posttest.