Measuring the value and impact of health library and information services: past reflections, future possibilities

To summarize the context, history and results of research studies conducted on the value and impact of health library and information services by the author since 1975 and to use this as a basis for examining ongoing developments related to evaluation research. To provide a comprehensive bibliography of library value and impact studies. Literature review and background based on personal involvement in the studies under discussion. The author's studies demonstrate an ongoing evolution of value and impact studies since the mid-1970s. In health sciences libraries, the approach taken to measuring value and impact has been strongly influenced by the type of research being conducted in the health sciences field as a whole. As a result, health sciences library researchers have become early adopters of methods that incorporate outcome and impact measures and rigorous research designs, and the concept of evidence-based library and information practice. The paper recommends that a range of research approaches from various disciplines be used to guide future evaluation research. Value and impact studies will continue to be important resources for evidence-based practice as health information professionals deal with evolving user needs and new ways of delivering information to a variety of audiences.