new definition asks that titles be reported as electronic if available in both print and electronic formats, and that titles be reported as purchased if available through both purchased and non-purchased arrangements. Serial titles are more accessible when they are delivered electronically, thus, in the revised definition, the instructions highlight the primacy of the electronic format when eliminating duplication among print and electronic titles. If a title appears in both print and electronic form and a library has acquired it through several different providers, it would be counted as a single, electronic, purchased title. This change has been successful in that more libraries are able to report data on serial titles (101 libraries) than were able to report data on serial subscriptions (90 libraries), indicating that the new definition is moving us in the direction of gathering data that are both collectable and useful. The accompanying table offers a comparison of the ARL Statistics data collected for serial subscriptions in 2005–06 and serial titles in 2006–07. The median number of serial titles reported (51,797) under the new definition is over 10,000 titles higher than the median number of serial subscriptions reported in 2005–06 (40,607). Most of the increase is in serial titles purchased (median: 39,113). As a result, the unit cost of serials has decreased as the definition shifted from subscriptions to titles. The number of serials not purchased did not change dramatically when the definition changed from subscriptions to titles. One should also note that there is a strong positive correlation between serial subscriptions under the old definition and RLI 262 19 FEBRUARY 2009 RESEARCH LIBRARY ISSUES: A BIMONTHLY REPORT FROM ARL, CNI, AND SPARC Current Serials (median) Purchased (median) Not Purchased (median) Average Unit Cost Titles (2006–2007) 51,797 (n=113) 39,113 (n=101) 9,861 (n=101) $192 (n=101) Subscriptions (2005–2006) 40,607 (n=113) 25,967 (n=90) 10,636 (n=90) $241 (n=89) A Comparison of Serial Titles in 2006–2007 and Serial Subscriptions in 2005–2006 Source: ARL Statistics 2006–2007 and 2005–2006. ARL Statistics: Redefining Serial Counts and Remaining Relevant in the 21st Century ( C O N T I N U E D )