Four configurations of MEDLINE alternatives that are evaluated. One important consideration is that, depending on the alternatives selected, the level of use of MEDLINE can vary considerably (10,000-28,000 uses per year in the model used). When costs are analyzed, per-use costs are relatively similar (ranging from $21.10 to $25.20) but total costs vary considerably ($251,000 to $590,000). Retrieval capability were found to be the most important factor for end users when choosing a system. Institutions, when looking at the issues associated with the selection of MEDLINE alternatives, must of course place primary importance on user needs. Other aspects must also be examined, and these can be grouped into three general and highly interrelated categories: system characteristics, management considerations, and cost to the institution and to users.