Unanswerable Reference Questions
The article by Mary Whisner, Reference Librarian at the University of Washington School of Law, is called Unanswerable Questions:
"I have encountered some types of unanswerable questions repeatedly: those that ask for a prediction, those that ask for data that hasn’t been gathered or documents that haven’t been released, and—perhaps most frustrating—those where the patron is sure of a few details of a document that are hard to match up with anything we can find. I’d like to discuss each of these types and then talk a little about what we do with the unanswerables (...) "
"Whether a question is truly unanswerable or simply stumps us, we serve ourselves and our patrons well if we explain our thinking and our research process. It’s not enough to say, 'I looked but I couldn’t find what you asked for.' If we explain where we looked and what we tried, it helps the patron understand why we weren’t able to find the answer. That might persuade the patron that the answer isn’t findable (with the resources available). Or the patron might come up with other ideas for searching—perhaps a clue that was omitted in the first request or a synonym for the search terms we’d used..."