We begin with an examination of the theories that participants offer regarding the causes of school failure, prisoners' return to crime, and unemployment. The theories are in a way the least important part of the investigation, as our central concern is the nature of the arguments people offer to support their theories, not the theories themselves. Nonetheless, all of the thinking to be examined in the remainder of the book will have these theories as its subject. It is therefore worthwhile to begin with a close look at them.

The interview on each topic begins in a very simple, straightforward way with the question “What causes —?” Subjects are free to respond in any way they like, briefly or at length. When the subject finishes speaking, the interviewer introduces the probe “Anything else?” as an encouragement to the subject to continue. When the subject finishes speaking in response to this probe, the theory is accepted as complete. If the subject's theory includes multiple causes, the subject is asked to identify which cause he or she sees as the major cause of the phenomenon, and it is this cause that the subject is then asked to argue with respect to in the remainder of the interview. (See appendix 1 for the complete interview.)

PEOPLE AS THEORISTS

It is first of all necessary to establish that subjects participating in the study indeed have causal theories about the phenomena they are asked about and are able to express these theories in the interview situation.