In this appendix, some of the statistical tests most commonly used (and misused) in biological research are discussed. These tests are used for comparisons among groups (e.g., t test and ANOVA). A number of other important areas (e.g., linear regression, correlation, and goodness-of-fit testing) are not covered. The purpose is to enable the reader to determine rapidly the most appropriate way to analyze data, and to point out some of the most common errors to avoid.