Building and mining a repository of design pattern instances: Practical and research benefits

Design patterns are well-known design solutions that are reported to produce substantial benefits with respect to software quality. However, to our knowledge there are no scientific efforts on gathering information on software projects that use design patterns. This paper introduces a web repository of design patterns instances that have been used in open source projects. The usefulness of such a repository lies in the provision of a base of knowledge, where developers can identify reusable components and researchers can find a mined data set. Currently, 141 open source projects have been considered and more than 4500 pattern instances have been found and recorded in the database of the repository. The evaluation of the repository has been performed from an academic and a practical point of view. The results suggest that the repository can be useful for both experienced and inexperienced users. However, the benefits of using the repository are more significant for inexperienced users.