Librarians often have brief communication accidents in attempting to u
nderstand reference questions as they ale initially presented, In this
linguistic analysis, examples obtained largely from self-reports by l
ibrarians were analyzed for evidence of phonological, syntactic, seman
tic, and pragmatic anomalies. These ''ill-formed queries'' were classi
fied into four main categories: (1) ''no-harm-done'' examples (usually
caused by acoustic failures); (2) unrecognized librarian-originated a
ccidents (usually involving pronunciation variants or homophones); (3)
secondhand communication accidents (where the user repeats an earlier
misunderstanding; and (4) creative reconstruction (where the user rec
onstructs the meaning of a forgotten term). The results may assist lib
rarians in understanding the linguistic reasons for common input failu
res and in learning communication strategies designed to avert or repa
ir such accidents. Specific interview techniques are recommended: rest
atement, open or neutral questions, and follow-up questions. This stud
y is part of a larger investigation in which discourse analysis is use
d to examine ill-formed queries for evidence of library users' mental
models of information systems.