Introduction

When researchers have collected their samples of data, they typically use statistical tools to help them test for:

1. Differences between groups of people (for example, between psychotics and normals, or between the genders).

2. Differences between experimental treatment conditions (for example, between children who viewed a violent film and those who didn't).

3. Relationships between variables (for example, between IQ score and number of siblings, or between high school GPA and success in college).

This program deals with point 3 -- the analysis of relationships, also known as correlation analysis.