Spoiled patterns: how to extend the GoF

Abstract

Design patterns were popularized by the GoF catalog in 1995. This catalog contains 23 design patterns which concern 23 design problems. Each pattern is detailed with its structure, its intent, and some information including applicability conditions and some possible variations which enable it to be re-used. In 1995, they were the cutting edge thought processes. We consider that design patterns have two major features. First, they are the result of emergent conceptions validated by a community through a well-defined acceptance process. They are a field of expert knowledge. Secondly, they must be as abstract as needed to be able to maximize their reusability. They constitute a compilation of best practices concerning object codes and designs. We propose to extend the GoF with a new concept that we have named “spoiled patterns”. They are midway between bad smells in design necessary to go ahead with a refactoring and a necessary learned lesson in order to explain anti-patterns. Each design pattern corresponds to some spoiled patterns. In this paper, we present how we have compiled the first spoiled patterns catalog, by carrying out several experiments with a lot of young inexperienced designers.