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

Data Collection Methods

Data may be collected in two different ways, quantitatively or qualitatively.

Quantitative data: Information that can be expressed in numerical terms, counted, or compared on a scale (e.g., the number of days a kid used marijuana in the past month).

Examples of a quantitative evaluation survey or tool include:

• Government Performance and Results Act, Youth Survey (12 years and over)
• Core Measures Initiative

Qualitative: Information that is difficult to measure, count, or express in numerical terms (e.g., the reasons a child reports using marijuana in the past month).

Examples of qualitative evaluation methods include:

• Focus groups
• Interviews
• Observational methods