The documentation of popular APIs is spread across many formats, from vendor-curated reference documentation to Stack Overflow threads. For developers, it is often not obvious from where a particular piece of information can be retrieved. To understand this documentation landscape, we systematically conducted Google searches for the elements of ten popular APIs.
All raw data as well as aggregated data are available in this online appendix. The data directory contains one directory per API, with five files each: input.txt lists all API elements along with the source URL; recent-input.txt lists all API elements used as recent elements; raw.csv contains, for each API element, all links returned by Google on the first page of search results, along with their domain and rank; aggregate.csv aggregates this data by domain and shows coverage (absolute and relative) and median rank for each domain; and recent-aggregate.csv shows the same data for recent API elements only.
The paper describing the details of data collection and analysis is available here (preprint).
We encourage other researchers to use this data to study API documentation returned by Google searches.