Object‐oriented patterns: lessons from expert systems
Tim Menzies · Software Practice and Experience · 1997
Three benefits are typically claimed for object-oriented (OO) patterns: (i) reusing parts of the conceptual models of old implementations; (ii) guiding the current development based on using successful previous developments; and (iii) communicating existing systems to newcomers. We will argue that a similar idea can be found in the expert systems literature dating from the early 1980s. The goal of KL or knowledge-level modelling (e.g. KADS) is to identify abstract patterns of inference that appear in many expert systems. Such abstract patterns of inference and program structure, it is argued, are productivity tools for the creation of software applications, i.e. KL argues for a similar reuse benefit as OO patterns. Recently, however, an alternative view has emerged. While such abstract patterns are good for communications and guidance, the reuse benefits may never be realised. Patterns may be best viewed as tools for structuring an argument, rather than recording a conclusion. © 1997 John Wiley & Sons, Ltd.