Data on re-shelving patterns, where available, is also useful. Librarians consider the potential an item has for in-library and reference use. They also draw upon their knowledge of Penn's academic programs, patterns of teaching and course offerings, the advice of faculty members and collection development policies in making storage decisions. In general, items which have circulated only once or twice in the last ten years or have no apparent circulation history at all are prime candidates for storage. In the case of multi-volume sets, librarians select the entire set for transfer unless there are strong reasons to do otherwise.
Journals raise their own issues.
Journals do not circulate, and therefore librarians weigh the in-house use of these materials in making their decisions. In principle, journals which were canceled some years ago may not be needed by current academic programs and hence are selected for Storage. Other journals may have ceased publication altogether, but are still essential. In some fields librarians break a journal run, sending older volumes to storage and keeping recent volumes on the shelves. Whether a journal is indexed or not is also a factor in selection for Storage.