COGNITIVE ACTIVITIES AND LEVELS OF ABSTRACTION IN PROCEDURAL AND OBJECT-ORIENTED DESIGN

The research reported in this article provides descriptions of design activities and of the evolving designs for expert procedural and exper t object-oriented (OO) designers and for novice OO designers who also had extensive procedural experience. Ten experienced programmers were observed while designing software that would serve as a scoring system for swim meet competitions. Talk-aloud protocols were collected and a nalyzed for different types of cognitive activities and strategies tha t occurred during the course of design. In particular, we analyzed bot h the design activities and the level of abstraction of the designs ov er the course of time for each group in order to examine the role of s everal design strategies described in the literature as central in pro cedural design. In the course of these analyses, we developed a generi c way (design template) of comparing the final designs of designers in different paradigms. Using this template, we analyzed the designs in terms of their completeness for different views at different levels of abstraction. Our analyses of procedural and OO designers-in terms of their cognitive activities, design strategies, and final designs-provi de a detailed comparison between design paradigms in practice. A varie ty of descriptive results are discussed in terms of positive transfer, interference, and implications for design training. Findings are also discussed in terms of the relation between tasks and design paradigms .