Models for projecting software defects from analyses of Ada designs are described. The research is motivated by the need for technology to analyze designs for their likely effect on software quality. The models predict defect density based on product and process characteristics. Product characteristics are extracted from a static analysis of Ada subsystems, focusing on context coupling, visibility, and the import-export of declarations. Process characteristics provide for effects of reuse level and extent of changes. Multivariate regression analyses were conducted with empirical data from industry/government-developed projects: 16 Ada subsystems totaling 149000 source lines of code. The resulting models explain 63-74% of the variation in defect density of the subsystems. Context coupling emerged as a consistently significant variable in the models.>

Results of an empirical study of software design practices in one specific environment are reported. The practices examined affect module size, module strength, data coupling, descendant span, unreferenced variables, and software reuse. Measures characteristic of these practices were extracted from 887 Fortran modules developed for five flight dynamics software projects monitored by the Software Engineering Laboratory. The relationship of these measures to cost and fault rate was analyzed using a contingency table procedure. The results show that some recommended design practices, despite their intuitive appeal, are ineffective in this environment, whereas others are very effective.

The organization of computer science education as an interdisciplinary program is described. First, various possible relationships among disciplines are traced, and the features of interdisciplinarity are explained. Next, a specific interdisciplinary program in computer science is introduced, including experiences with the administration and operation of the program. An appraisal of the interdisciplinary approach to computer science education follows. The advantages are significant: a lower cost program, a more adaptive program, and one that is better able to treat the interfaces of computer science with other areas. Such a favorable report suggests that the interdisciplinary approach merits consideration, especially by colleges which want to offer a computer science degree but have limited funds.