Using SPSS with the data imported in Exercise 3.7, determine the percentage of times when the observer (myself ) gave the wrong response by looking at the Accuracy variable.

Plot and describe the distribution of reaction time data.

The next two exercises refer to a large data set in Appendix D. The data can also be downloaded from the Web at These data come from a research study by Howell and Huessy (1985), which is described at the beginning of the appendix. We will refer to them throughout the book