Usage Analysis for the Identification of Research Trends in Digital Libraries

The analysis of user logs from large-scale digital libraries offers new opportunities to assess research trends in an institution's user communities. We describe the application of a methodology to derive weighted journal relationship networks from reader logs at the Los Alamos National Laboratory's Research Library during 1998 and 2001. A journal impact metric is defined that derives journal impact from the structural features of the generated journal relationship networks, much in the same manner Google's PageRank evaluates the impact of web pages for a given subject on the basis of its context of hyperlinks to other pages. A comparison of this reader impact metric to the ISI Impact Factor values for the same journals in 1998 and 2001 allows us to detect and interpret community-specific research trends where the LANL community deviates from Usage Analysis for the Identification of Research Trends in Digit... http://www.dlib.org/dlib/may03/bollen/05bollen.html 1 of 21 12/9/13 4:02 PM more general trends as indicated by changes in the Institute for Scientific Indexing (ISI) Impact Factors during those same years. Such analysis yields information to aid digital library managers to improve the evaluation of not only which parts of the collection are most highly valued by their local community, but it also detects research trends in user communities as they evolve over time.