1. Journal Citation Reports® – “the JCR” February 2009 Enhancements
GSS – Thomson Reuters, Scientific Business, A&G
January 2009

2. Journal Citation Reports ® – Forthcoming Enhancements
For decades, the Journal Citation Reports (JCR) has served as a foundation of journal collection development, characterization, and evaluation within academic and government libraries worldwide. In early 2009 an unprecedented enhancement and release of the JCR is scheduled, incorporating new metrics and information to complement the high-profile Impact Factor.

3. Journal Citation Reports ® – Forthcoming Enhancements
Why add additional metrics to the JCR? Our objective in including this new information is to expand one’s evaluative perspective on scholarly journals, to provide a more thorough and well-rounded overview of their overall impact and influence.

4. New Metrics & Information Five-Year Impact Factor
Journal Citation Reports ® – Forthcoming Enhancements
New Metrics & Information
Five-Year Impact Factor
Rank-in-Category Tables
Box Plots
Illumination of Journal Self-Citations
Eigenfactor MetricsTM: EigenfactorTM and Article InfluenceTM

5. Journal Citation Reports ® – Forthcoming Enhancements
Citation Behavior, variance among disciplines: Some fields are very fast moving, particularly within the life sciences, and published research gets cited at a relatively rapid pace. Research in other fields, mathematics for example, makes its impact more slowly over an extended period of time.
2006 Impact Factor Years

6. Journal Citation Reports ® – Forthcoming Enhancements
Introduction of a 5-Year Impact Factor: To better gauge the impact of journals within fields where influence of published research evolves over a longer period of time than presented by the traditional Year Impact Factor.
Immunology
Impact Factor is based on two years of cited journal content – cites in the current year to journal material published in the prior two years.
A 5-Year Impact Factor is based on cites in the current year to journal material published in the prior five years.
Note that in this display of top Immunology journals the 5-Year Impact Factor is, with the exception of one journal, lower than the traditional 2-Year Impact factor.
Immunology is a life science discipline that is typically “fast moving” and therefore this makes perfect sense that articles are cited more quickly, and may lose some citation impact after the first few years.

7. Journal Citation Reports ® – Forthcoming Enhancements
Introduction of a 5-Year Impact Factor: To better gauge the impact of journals within fields where influence of published research evolves over a longer period of time than presented by the traditional Year Impact Factor.
Geology
Geology
Impact Factor is based on two years of cited journal content – cites in the current year to journal material published in the prior two years.
A 5-Year Impact Factor is based on cites in the current year to journal material published in the prior five years.
Within this display of Geology journals however, the 5-Year Impact Factor is in every case higher than the traditional 2-Year Impact Factor. In contrast to Immunology for example, published research with Geology typically takes more time to fully realize its impact.

8. Journal Citation Reports ® – Forthcoming Enhancements
Rank in Category table: Many journals maintain an editorial scope that necessitates their inclusion in more than one JCR category. To better reveal the influence of a journal in all assigned categories a Rank in Category table will display each category in which the journal appears along with rank in the category and the Quartile in which the journal is placed in that category - based on Impact Factor.

9. Journal Citation Reports ® – Forthcoming Enhancements
Category Box Plot: A category Box Plot accompanies the Rank in Category table. The spacing between the different parts of the box, the quartiles, helps indicate the degree of dispersion of impact of journals within the category. View the journal's Impact Factor in the context of all Impact Factors for the journal's category as depicted by the graph – envisioning a line at the position of the journal’s Impact Factor helps one to better comprehend the display.
The box plot depicts the distribution of Impact Factors for all journals in the category. The horizontal line that forms the top of the box is the 75th percentile. The horizontal line that forms the bottom is the 25th percentile. The horizontal line that intersects the box is the median Impact Factor for the category. The cross represents the mean value.
Horizontal lines above and below the box represent maximum and minimum values that are no more than 1.5 times the span of the interquartile range, which is the range of values between the 25th and the 75th percentiles. These lines are commonly referred to as "whiskers."
An open circle represents an outlier, which is a single value greater or less than the extremes indicated by the whiskers

10. Journal Self-Citation
Journal Citation Reports ® – Forthcoming Enhancements
Journal Self-Citation
Journal Self-Citation itself is not an inherently “bad” practice.
Authors of course cite related research and this may have been published in the journal to which one in turn submits a paper for publication.
However -- 80% of all journals listed in the JCR Science Edition have self-citation rates of less than 20%. Based on trends within a category we can get an idea of what may be excessive self-citation, which weakens the integrity of the journal’s Impact Factor.

11. Journal Citation Reports ® – Forthcoming Enhancements
Illumination of Journal Self-citation Rates: To provide one the ability to easily compare self-citation rates among journals particularly as this influences Impact factor calculations.
Category: Materials Science, Composites

12. Journal Citation Reports ® – Forthcoming Enhancements
Eigenfactor MetricsTM: EigenfactorTM and Article InfluenceTM: To compliment Impact Factor and other JCR metrics by providing a broader perspective on Journal Influence through specific measures now widely accepted by the scholarly community These metrics are developed through The Eigenfactor Project™ -- a non- commercial academic research project sponsored by the Bergstrom lab in the Department of Biology at the University of Washington. –

13. Journal Citation Reports ® – Forthcoming Enhancements
EigenfactorTM Score:
Scholarly references join journals together in a vast network of citations. The Eigenfactor Score algorithm uses the structure of the entire network to evaluate the importance of each journal, cutting across all disciplines. Self-citations are excluded.
This corresponds to a simple model of research in which readers follow chains of citations as they move from journal to journal.
Eigenfactor calculations take into consideration a 5-year span of citation activity utilizing data from the Journal Citation Reports.
Journals are considered to be influential if they are cited often by other influential journals.
Eigenfactor accounts for the fact that a single citation from a high-quality journal may be more valuable than multiple citations from peripheral publications.
In order to make these calculations, computing an Eigenfactor score in understandably more complex and therefore less transparent than Impact Factor calculations. Most importantly, Eigenfactor is concerned with measuring the total contribution/value of a journal to the scientific community while Impact Factor measures the average impact of an article published in a given journal.
Impact Factor includes a much greater element of “timeliness”, given its 2-yr window of cited works – and focuses on one-to-one citation relationships among journals. Simple and direct, easy to understand, these are strengths of the Impact Factor as well as the 5-year Impact Factor which simply takes into consideration a greater window (5 years) of cited works than the traditional Impact factor.
However, describe Eigenfactor this way -- Eigenfactor measures the total influence of a journal on the scholarly literature or, comparably, the total value provided by all of the articles published in that journal in a year.
To help clarify, contrast with Impact Factor -- The Eigenfactor Score provides a measure of the total influence that a journal provides, rather than a measure of influence per article. Impact Factor, by contrast, presents an average per-article influence of a given journal.
An alternate description – Eigenfactor score accounts for not just the raw citations to Journal X (such as Impact Factor), but the importance of the journals citing the journals that account for the raw citations to Journal X. 
OR –
The Eigenfactor Score of Journal X is defined as the percentage of the total weighted citations that Journal X receives from all source journals within the JCR.

14. Article InfluenceTM Score:
Journal Citation Reports ® – Forthcoming Enhancements
Article InfluenceTM Score:
As with Eigenfactor Score, Article Influence Score:
Uses the structure of the entire citation network to evaluate the importance of each journal, based on JCR data.
Does not consider self-citations
The calculation of Article Influence Score does in fact incorporate Eigenfactor Score.
However, as Eigenfactor Score can be described as presenting the total collective value provided by all of the articles published in a journal in a year – Article Influence Score measures the average influence of individual articles appearing in the same journal, translating to the importance of an article published in that journal.
Because it does present an average for article-level influence, Article Influence is more like the Impact Factor than Eigenfactor Score – though keep in mind the methodology is quite different and therefore provides a perspective different from but complimentary to Impact Factor.
Compare only --
Eigenfactor Scores to other Eigenfactor Scores
Article Influence Scores to Other Article Influence Scores
AND, just as with Impact Factor, make comparisons for journals within and not between disciplines.
An analogy that may help to differentiate things:
Think of a Journal as diamond mine. Eigenfactor Score represents the value of the contents of the entire mine relative to all other diamond mines (journals) in the world.
Article Influence represents the average value of a typical diamond (an article) taken from that mine.

15. Journal Citation Reports® – “the JCR” February 2009 Enhancements
GSS – Thomson Reuters, Scientific Business, A&G
January 2009