KNOWLEDGE EXPLOITED BY EXPERTS DURING SOFTWARE SYSTEM-DESIGN

High-level software design is characterized by incompletely specified requirements, no predetermined solution path, and by the integration of multiple domains of knowledge at various levels of abstraction. The application of data-driven knowledge rules characterizes expertise. A verbal protocol study describes these domains of knowledge and how experts exploit their rich knowledge during design. It documents how designers heavily rely on problem domain scenario simulations throughout solution development. These simulations trigger the inferences of new requirements and complete the requirement specification. Designers recognize partial solutions at various levels of abstraction in the design decomposition through the application of data-driven rules. Designers also rely heavily on simulations of their design solutions. but these are shallow, that is, limited to one level of abstraction in the solution. The findings also illustrate how designers capitalize on design methods, notations, and specialized software design schemas. Finally, the study describes how designers exploit powerful heuristics and personalized evaluation criteria to constrain the design process and select a satisfactory solution. Studies, such as this one, help map the road to understanding expertise in complex tasks. © 1990 Academic Press Limited.