Introduction
FOCUS is a context-aware collaborative-filtering recommendation system that exploits cross relationships among OSS projects to suggest the inclusion of additional API invocations and concrete API usage patterns. The current implementation targets Java code specifically. Implementing a collaborative-filtering recommendation system requires to assess the similarity of two customers, i.e., two software projects. Existing approaches consider that any two projects using an API of interest are equally valuable sources of knowledge. Instead, we postulate that not all projects are equal when it comes to recommending usage patterns: a project that is highly similar to the project currently being developed should provide higher quality patterns than a highly dissimilar one. Our collaborative-filtering recommendation system attempts to narrow down the search scope by only considering the projects that are the most similar to the active project. Therefore, methods that are typically used conjointly by similar projects in similar contexts tend to be recommended first. We incorporate these ideas in a new context-aware collaborative filtering recommender system that mines OSS repositories to provide developers with API FunctiOn Calls and USage patterns: FOCUS. Our approach employs a new model to represent mutual relationships between projects and collaboratively mines API usage from the most similar projects.
FOCUS in action