ABSTRACT
The literature relating to the evaluation of library services can be traced back many years. Nevertheless, diagnostic microevaluations (i.e., detailed analytical studies intended to identify causes of failures and suggest possible remedies for these), based on objective methods, have been applied to information services for only a short time. In fact, the prototypical diagnostic studies appear to be those applied to bibliographic searching services (e.g., Lancaster, 1968) some fifteen to twenty years ago. Since that time, somewhat equivalent procedures have been applied to the document delivery capabilities of libraries (e.g., Kantor [1976], Saracevic et al. [1977], Schofield et al. [1975], Urquhart and Schofield [1971, 1972]).
