This chapter introduces a study of natural everyday human usage of the UNIX operating system and its command line interface. Analysis of the data collected is central to the pursuit of knowledge of user behavior when interacting with generalpurpose environments. The chapter begins by describing UNIX and gives reasons why it is an appropriate vehicle for research. Section 2.2 reviews several methods of data collection used with previous UNIX investigations, and Section 2.3 describes the details of the current study. Analyses of data are deferred to later chapters.

Choosing UNIX

Why perform natural studies on UNIX, with its baroque and outdated user interface, instead of controlled experiments on a modern system? This section starts by advocating a natural study for exploratory investigation of human–computer interaction. After recognizing several pragmatic problems with such investigations, UNIX is introduced and its choice is justified.

Natural studies

The thrust of the work presented in this book is that it is possible to capitalize on patterns evident in human–computer interaction by building special user support tools. A prerequisite is to “know the user” (Hansen, 1971). One way to accomplish this goal is through analyzing everyday natural user interactions with current systems so that existing patterns of activity can be discovered and exploited. Hanson, Kraut, and Farber (1984) justify this approach by contrast with traditional controlled experimentation.