Personal experience working in that community and other communities for a prolonged period of time, as well as the first-hand experience of many other developers I've worked with, and the second-hand reports of an even larger set of developers.
I'm also aware of projects to do more formal analysis of various FOSS communities, such as FOSS Heartbeat.
But in the meantime, the plural of "anecdote" is absolutely "data" for sufficiently large values of "plural".
> the plural of "anecdote" is absolutely "data" for sufficiently large values of "plural".
I disagree, but I doubt we're going to resolve that here. To me, "the plural of anecdote is data" means "I can't be bothered to figure out whether the information I have is actually representative of the population".
