An analysis of the differences between density‐of‐use ranking and raw‐use ranking of library journal use

Reports of journal titles ranked by use with space and cost information included for each title can provide a means for making certain objective journal collection development decisions. Each title can be assessed in relation to the others and the data for all titles can be cumulated so that decisions can be made at various cutoff points. Simple ranking of titles by raw use (RUR) may be inadequate and should be adjusted by some measure to allow for how much of the title is available to the user at the time of the collection of the use data. If the raw‐use frequency of a title is divided by the actual linear shelf space of the title's file, a “density‐of‐use” frequency is obtained. If these frequencies are then ranked, a “density‐of‐use rank” (DUR) is formed. Some differences between RUR and DUR have been analyzed. Some evaluation of the quality of the differences has been made. There were significant changes in title ranking above random chance when an RUR was adjusted to become a DUR. At 80% of the total use of the entire collection, the number of titles in the DUR increased almost twofold over those in the RUR. Furthermore, less linear shelf space was used and the cost increase was not great. The number of potential unsatisfied title uses at two different cutoff levels in the rankings was less in the DUR.