What topics does Wikipedia cover? Has the coverage changed over time? These and similar questions are examined using 1001 random articles sampled in December, 2015. The 18 categories and subcategories are dominated by biographies (27.8% of all articles), with biographies of men (23.8%) being 5.8 times as common as women (4.1%). Sports biographies (9.5%) form over a third of all biographies. All articles on sports total 16.0% of the sample. Geography (17.8%) and Culture & Arts (15.8%) are other major categories, with Science & Math (3.5%) having the lowest proportion of the categories in the sample. These proportions are fairly stable over time. Almost 90% of page views go to the 20% of articles with the highest page views.
The sample is intended to be used to investigate additional questions as they arise, with additional data gathered as necessary. As an example, 27 matched pairs of biographies of men and women were formed and the growth, in bytes and words of text, of these articles was recorded over 5 years from their starts. The results suggest that, on average, all bios more than double in size over 5 years, but that bios of men start about 30% larger than bios of women, and that they grow at a slightly faster rate. Modified data from ORES was also examined and appears to be a useful resource for addressing these, and similar questions.