The A. R. Dykes Library of the Health Sciences collects resources on topics of current interest which specifically support the Medical Center's programs and which show the promise of substantial use. Usage studies help inform decisions about renewals and retention of resources. We analyze standardized methods for counting the number of uses for electronic products, interlibrary loan requests to determine if we should be purchasing rather than borrowing materials, or vice versa, and circulation statistics for print materials. Overlap with other resources is also taken into consideration. Selection of library materials involves the planned identification and review of items best-suited to strengthen Dykes Library resources for KUMC's missions in education, research, patient care, and communities. Subject relevance, intellectual content, level of presentation, and reputation of author and publisher are components of our evaluation criteria.