The 2010 Journal Citation Reports data were released today, June 28. This first JCR was published as volume 9 of the 1975 Science Citation Index™ (back then, the SCI was only 8 volumes!). All the familiar features of the JCR are present for the 36th time – Journal Impact Factors, the citing-cited journal networks, total citations, cited half-life. After all this time, what could be new?

New data: The JCR, as most users know, analyzes one year of citation data from the Thomson Reuters citation indexes. Each year is a new year of data, that represent citations that will be part of no prior (or future) JCR data. Though simple, this fact is often overlooked. The 2010 JCR began with a dataset of 49 million cited references indexed by Thomson Reuters from any of over 20,000 sources in science, social sciences, arts & humanities, book and journal proceedings volumes. The result is new data for the 10,196 titles in the JCR (8005 in the Sciences edition, 2678 in the Social Sciences edition – 487 titles are listed in both editions).

New Categories: Two new categories will appear in the 2010 JCR – one in the Science Edition, one in the Social Sciences edition. Categories are created by the Editorial Development specialists when a topic is sufficiently cohesive from a citation standpoint, and has a robust collection of dedicated journals in our products.

Science: Primary Health Care

This is not exactly a new topic – and most of the journals in the category have been covered for many years. Internal review of our collection, as well as discussion with the community identified Primary Care (or Family Medicine) as a medical specialty that had a mature set of journals which were related to general medicine, internal medicine and various aspects of health services, but were also a distinct and interrelated set. View the description of the Primary Health Care category here.

Social Sciences: Cultural Studies

This category has allowed to collect and compare journals from a variety of social science areas that allow an interdisciplinary view of culture. Many of the journals for the Cultural Studies category have been added to Thomson Reuters this year (2011), and will not appear in the JCR until next year. View the description of the Cultural Studies category here.

New Journals: 1075 titles will receive their first Journal Impact Factor in 2010 data (view the list here). This large number is the result of two recent initiatives at Thomson Reuters.

1) The expansion of coverage to align to the increasingly global population of users of Web of Science™ (read more here). Many of the journals identified through this project were added to coverage with their 2008 issues; in 2010, we now have a complete three years of source materials – enough to publish an accurate Journal Impact Factor.

2) When journals were added to coverage in 2010, our indexing didn’t start with the 2010; we included 2009 and 2008 as well. In fact, we indexed as far back as 2006 if that would allow us to obtain the first volume. This allows us to publish a Journal Impact Factor for most journals within a year of their selection for Web of Science.

The 2010 JCR is the largest data set we’ve ever published, containing 10,196 titles (view the list here) – with multiple metrics and a rich descriptive data set prepared for each journal, and for each category.

New and Old: The JCR isn't just new, it’s also old. It has an unrivalled history and reputation based on 35 years of consistent publication, experience, study, and review of our content, processes and policies. To see the "all new" JCR 2010, go to Web of Knowledge (www.webofknowledge.com).