Appendix Introduction

Statistical procedures are tools for dealing with data. Some people find them fascinating for their own sake, just as some become intrigued by the beauty of a saw or a hammer. But most of us, most of the time, care about statistics only to the extent that they help us answer questions. Statistics become interesting when we want to know our batting average, or the chance that our favorite candidate will be elected, or how much money we’ll have left after taxes. In psychology, statistics are interesting when they are used to analyze data in ways that help answer important psychological questions.

Some of the basics of statistics are described in Chapter 2. The main purpose of the first three sections of this appendix is to supplement that discussion and make it more concrete by providing some examples of statistical calculations. The fourth section (Supplement on Psychophysical Scaling) supplements the discussion of Fechner’s work in the section on psychophysics in Chapter 7.