While only in the past ten years have large numbers of people been engaged in computer programming, a small body of studies on this activity have already been accumulated. These studies are, however, largely atheoretical. The work described here has as its goal the creation of an information processing theory sufficient to describe the findings of these studies. The theory postulates understanding, method-finding, and coding processes in writing programs, and presents an explicit model for the coding process.

In a large variety of programming situations, a programmer is required to understand a program that someone else has written. A model has been created for the behavior seen in the verbal protocol of a programmer on a sample understanding task. The model is based on a theory of understanding which stresses the role of the programmer's apriori hypotheses or guesses about the program structure. Organization of the model is that of a production system, a structure which appears particularly well-suited to the asynchronous, non-sequential nature of the input.

Production systems have recently found considerable favor as the control structure for systems in artificial intelligence. This work has lead other researchers to suggest the creation of languages which have production systems as a primary or alternative control structure. This paper explores some of the possibilities available in these languages; an experimental language with a production system control structure is presented, along with an example program written in it. Appropriate application domains for languages of this type are discussed, and the potential for using them with future hardware architectures is explored.