Needles in a haystack: Using interlibrary loan data to identify materials missing from a library's collection

A study conducted at the University of Illinois at Urbana-Champaign (UIUC) Library examines data from unfilled ILL requests to determine the status of materials housed in the Main Bookstacks of the library's collection. The study focuses on ILL requests that were not filled due to material missing from the collection. Results of the study identified training issues with staff and student employees, indicated that high use materials were more subject to loss, recognized that overcrowding of the collection contributed to error, and noted that maintenance shifting of materials created additional problems for locating materials. Analysis of the data resulted in a suggested procedure to use unfilled ILL requests to update the library's OPAC for more accurate representation of the status of materials in the collection.