API documentation and software community values: a survey of open-source API documentation

Studies of what software developers need from API documentation have reported consistent findings over the years; however, these studies all used similar methods--usually a form of observation or survey. Our study looks at API documentation as artifacts of the open-source software communities who produce them to study how documentation produced by the communities who use the software compares to past studies of what software developers want and need from API documentation. We reviewed API documentation from 33 of the most popular open-source software projects, assessed their documentation elements, and evaluated the quality of their visual design and writing. We found that the documentation we studied included most or all the documentation elements reported as desirable in earlier studies and in the process, we found that the design and writing quality of many documentation sets received considerable attention. Our findings reinforce the API requirements identified in the literature and suggest that the design and writing quality of the documentation are also critical API documentation requirements that warrant further study.