Detecting API usage obstacles: A study of iOS and Android developer questions

Software frameworks provide sets of generic functionalities that can be later customized for a specific task. When developers invoke API methods in a framework, they often encounter obstacles in finding the correct usage of the API, let alone to employ best practices. Previous research addresses this line of questions by mining API usage patterns to induce API usage templates, by conducting and compiling interviews of developers, and by inferring correlations among APIs. In this paper, we analyze API-related posts regarding iOS and Android development from a Q&A Web site, stackoverflow.com. Assuming that API-related posts are primarily about API usage obstacles, we find several iOS and Android API classes that appear to be particularly likely to challenge developers, even after we factor out API usage hotspots, inferred by modelling API usage of open source iOS and Android applications. For each API with usage obstacles, we further apply a topic mining tool to posts that are tagged with the API, and we discover several repetitive scenarios in which API usage obstacles occur. We consider our work as a stepping stone towards understanding API usage challenges based on forum-based input from a multitude of developers, input that is prohibitively expensive to collect through interviews. Our method helps to motivate future research in API usage, and can allow designers of platforms - such as iOS and Android - to better understand the problems developers have in using their platforms, and to make corresponding improvements.