9º World Congress on Health Information and Libraries

Salvador, Bahia - Brazil, September, 20 to 23 - 2005


4th Regional Coordination Meeting of the VHL

September, 19 to 20 - 2005

Content overlap of the Elsevier ScienceDirect Subject Collections: book series, current journals, and journal backfiles

  • Assistant Director of Acquisitions and Coordinator of Electronic Resources, Texas A & M University Libraries  - USA

Content overlap of the Elsevier ScienceDirect Subject Collections: book series, current journals, and journal backfiles

Elsevier markets its journal and book series content on the ScienceDirect site as subject collections. As of April 2005, Elsevier has released 5 book series subject collections, 24 current journal subject collections, 23 journal backfile subject collections, and 19 journal backfile collection supplements. One additional supplement, Medicine and Dentistry, is scheduled for release during 2005. At present, Texas A & M University is subscribed to all available book series, to all current Elsevier journal titles, and to all subject backfile collections. We will be considering the subject backfile collection supplements once all have been released.
Nearly all of Elsevier’s subject collections have extensive content overlap with one another, which a library must take into account when negotiating the price of subscribing or purchasing. In this study, I have calculated overlap of the current journal collections and the book series collections as a simple percentage of titles. As an example, the Medicine and Dentistry Collection of current journals has a 49.8% overlap of titles with all other available collections. The Nursing Collection has a 46.1% overlap with the Medicine and Dentistry Collection alone, and a total overlap of 80.5% with all collections. The book series collections similarly show overlap of content.
The backfile collections provide content coverage back to v.1 n.1 for all titles in each colle c tion. I have measured overlap as expressed in “subscription years” for the titles that make up the collections, based on information available on the ScienceDirect site. My findings show that the extent of overlap ranges from 25.6% for the Chemistry Collection with all other Collections, to 94.4% for the Veterinary Medicine Collection with all other collections. The subject backfile collection supplements released thus far likewise show overlap of content.
In this paper I will present the methodology used to calculate overlap among the book series collections, the current journal collections, and the journal subject backfile collections and supplements. I will review the results of the study showing overlap and unique content for each subject collection for the book series, and for the current and the backfile journal collections and supplements.