In the reference interview, the library user's information need can of
ten be clarified by asking questions that elicit his or her reasons fo
r presenting a reference query. However, librarians are often advised
to avoid using the question, ''Why do you want this information?'' Thi
s article draws on theory from linguistics (particularly speech act th
eory), philosophy, and cognitive science to show how the ambiguous nat
ure of ''why'' questions may lead to unproductive or even hostile resp
onses. The key to using ''why'' questions successfully in the referenc
e interview lies in a theoretically based understanding of the form an
d function of these questions in their social context. Two main strate
gies, contextualization and the use of neutral questioning, are sugges
ted for resolving this conflict in practice.