Suppose you want to answer some broad question about Wikipedia. Is it any good? What subjects does it cover? In what proportions? Is there much vandalism?

Finding a truly accurate answer would mean reading every article. However, Wikipedia has quite a few articles. Studying a random selection is a more practical approach to get a grasp on these questions – and compiling this sample is as simple as hitting Special:Random a bunch of times to record what comes up.

Random pages tests by various editors can be found in Category:Random pages tests, although the category is not comprehensive. The concept of random sampling is not exactly original to Wikipedia; indeed, various editors seem to have independently conceived the idea in Wikipedia's context several times over. The earliest tests date back to 2003. The number of articles in these tests ranges from as few as ten to as many as one thousand.