I've used the quotation "The plural of anecdote is not data" in various talks over the years, never knowing the original source. I searched the usual places (though clearly not hard enough!), but never figured out whom it should be attributed to. So I was pleased to learn that John Myles White had discovered the source: Raymond Wolfinger (presumably the political scientist from Berkeley). This attribution comes in this 2004 email from Fred Shapiro, editor of the Yale Dictionary of Quotations:
I [Shapiro] e-mailed Wolfinger last year and got the following response from him:
"I said 'The plural of anecdote is data' some time in the 1969-70 academic year while teaching a graduate seminar at Stanford. The occasion was a student's dismissal of a simple factual statement -- by another student or me -- as a mere anecdote. The quotation was my rejoinder. Since then I have missed few opportunities to quote myself. The only appearance in print that I can remember is Nelson Polsby's accurate quotation and attribution in an article in PS: Political Science and Politics in 1993; I believe it was in the first issue of the year."
So I've been using the quotation wrong all this time! I think I'm going to stick with "The plural of anecdote is not data", though: the word "anecdote" to me suggests information surrendered, not collected, and it's the implication of reporting bias that makes the quote so apposite for statisticians.
Linguist List: Re: "Plural of anecdote is data" (Ray Wolfinger)