Not all Journals are Created Equal! Using Impact Factors to Assess the Impact of a Journal Objectives: At the end of this talk, the participant will be able to: 1. Define Impact Factor (IF) 2. Explain how the impact factor relates to finding the "best" journal in which to publish. 3. Find the impact factor of a journal using the LRC’s Electronic Resources The man who started it all! Eugene Garfield The article that got the ball rolling: Why is this different? Based on law indexing (Shepard’s Citations) 1873 Subject indexes to scientific literature were in existence Garfield suggests that each article is given a code and all works that cited that article would be linked to the original article. First mention of Impact Factor Garfield recommends keeping track of who cited the paper. “In effect, the system would provide a complete listing, for the publications covered, of all the original articles that had referred to the article in question.” … Such an “impact factor” may be much more indicative than an absolute count of a scientist's publications.” Here impact factor refers to the impact of the article. Impact Factors for Journals In the early 1960’s Irving H. Sher and Eugene Garfield created the Journal Impact Factor to help select journals for Science Citation Index (SCI). They knew that a core group of highly cited large journals needed to be covered in SCI, but they also wanted to include the small, but important review journals which would not be included if they relied only on publication or citation counts. Created the Journal Impact Factor Journal Impact Factor Formula The number of times articles published in (2 years) were cited by indexed journals Total number of citable items (2 years) In Simpler Terms The impact factor is a measure reflecting the average number of citations to articles published in science and social science journals. Other Methods Eigenfactor H Index (or H factor) Immediacy index Eigenfactor • Developed by Jevin West and Carl Bergstrom at the University of Washington, • Journals are rated according to the number of incoming citations, with citations from highly-ranked journals weighted to make a larger contribution to the Eigenfactor than those from poorly-ranked journals. • Eigenfactor score scales with the size of a journal. • To allow per-article comparisons using the Eigenfactor approach, the Article Influence score scales Eigenfactor score by the number of articles published by the journal and thus is directly comparable to impact factor. Eigenfactor (cont) For more information, go to : http://Eigenfactor.org H Factor or H Index Index that attempts to measure both the productivity and impact of the published work of a scientist or scholar. A scholar with an index of h has published h papers each of which has been cited by others at least h times. Serves as an alternative to more traditional journal impact factor metrics in the evaluation of the impact of the work of a particular researcher Immediacy index Measure of topicality and urgency of a scientific journal Number of times articles published in year x were cited in indexed journals during same year. Number of articles, reviews, proceedings or notes published in year x What does it all mean? How do Impact factors help you find the best journal in which to publish? Limitations of the Impact Factor Self-citations Many times editors insist that authors cite works in that journal Some disciplines tend to cite more than others Journals change their names thus affecting impact factor for approximately two years Does not take into account negative citations How do I find a journal impact factor? Use the LRC’s Electronic Resources to go to Web of Science Click on Additional Resources to find Journal Citation Reports Journal Citation Reports JCR JCR distills citation trend data for 10,000+ journals from more than 25 million cited references indexed by Thomson Reuters every year Science Edition and Social Sciences Edition released annually Science Edition covers 7,200+ journals in 171 subject categories Social Sciences Edition covers 2,100+ journals in 55 subject categories First log in to ER and find Web of Science Access JCR from the Web of Knowledge Scenario I (We all have our dreams!) You have written an article and would like to have the most visibility possible. You have a choice between publishing in Science and Nature. Which should you choose, based on Impact Factor? Search for individual journals Subject Categories View Journal data Sort journals in the category Full Record Page Journal Rank in categories Journal Rank in categories Journal self citation To provide one the ability to easily compare self-citation rates among journals particularly as this influences Impact factor calculations. Category Impact Data Category Data – Median and Aggregate Impact Factors The Median Impact Factor for the subject category of Pediatrics is 1.252 The Aggregate Impact Factor for Pediatrics is 1.932 Access to JCR from the Web of Science Impact Factor Trend Graph •Entry point into JCR from Web of Science •Indicates the Journal’s Impact Factor over the latest five years Using JCR Wisely You should not depend solely on citation data in your journal evaluations. Citation data are not meant to replace informed peer review. Careful attention should be paid to the many conditions that can influence citation rates such as language, journal history and format, publication schedule, and subject specialty. The number of articles given for journals listed in JCR include primarily original research and review articles. Editorials, letters, news items, and meeting abstracts are usually not included in article counts because they are not generally cited. Journals published in nonEnglish languages or using non-Roman alphabets may be less accessible to researchers worldwide, which can influence their citation patterns. This should be taken into account in any comparative journal citation analysis.