A top-down approach to teaching an introductory computer science course

Reviewer: Terry Alan LePera

The goals and organization of a first course for computer science majors (CS1) that the author has developed and taught are described well. This course uses Ada and stresses top-down methodology, with its emphasis on conceptualization and organization of problem solutions via high-level modular programming. The author effectively argues that the traditional emphasis on syntax and small details in the first course conflicts with the goal of eventually having the student appreciate and understand “the problems involved in the analysis and implementation of large software systems.” He gives a topical course outline followed by brief descriptions of major course components. Key parts of his approach are starting students with instructor-supplied packages and having them write programs consisting of calls to procedures found in those packages; much consideration of top-down design, stepwise refinement, and general software engineering principles; and delaying implementation details such as selection and iteration structures until after the course's midpoint. The presentation is honest: the author admits that his CS1 students have encountered problems with coding in CS2. The paper describes one option for CS1. The use of Ada, though an important topic for discussion, is not as important as the software engineering orientation. The course supports the goals of the computer science program at Hilburn's institution and those of the ACM for software engineering [1]. An open question is whether a CS1 with this emphasis can support other visions of an undergraduate computer science program. The paper presents specific information on using Ada in CS1 and brings to mind important questions about current directions in computer science education and the discipline itself.