期刊影响因子分析,Journal Citation Reports - Journal impact factor,Essential Science Indicators,Citation and citation analysis,Citation Analysis via Peer Assessment,50 years ago,Garfield, E. “Citation indexes for science: A new dimension in documentation through association of ideas.” Science, 122 (3159), p.108-111, July 1955.,Cited References association of ideas of its author,Citation Indexes new approach to subject control of the literature of science,2004,Cited References,2000,1998,2001,1993,2003,Times Cited,2003,2004,Cited References,Paper/Article,Citing papers,How to define “citation”?,利用引文分析进行科研评估的理论基础: Normative Perspective on citations 美国社会学家罗伯特默顿 (Robert K. Merton): 科学的规范结构 文献引用的动机 Citation motivation: 原文献的科学价值 Citation Impact, Influence, Importance, Performance 科学期刊在同行科学家的交流中起着根本的作用。即科学文献能够代表科学活动以及表现不同分支学科之间关系。在整个期刊系统中，可以区分出“重要”的国际性期刊 学术文献被重要的期刊文献引用的次数是这一文献的影响或国际显著性的一种度量Moed et al., The use of bibliometric data for the measurement of university research performance, Research Policy, 14, 131-149,1985;Oppenheim, C. Journal of Documentation, 1995,引文分析的前提,Web of Science and its offspring,Web of Science,Journal Citation Reports,Journal Impact Factor,Stats by journal,Stats by address,Essential Science Indicators,Baselines,Customize,Research Services Group National Science Indicators Institutional Citation Reports Topic Citation Reports etc,Web of Science and its offspring,Article-level vs. Journal-level data,Science Citation Index Expanded,Web of Science,Journal Citation Reports,Journal Impact Factor,Stats by journal,Journal Citation Reports 独特的多学科期刊分析评价工具,自1997年以来的数据： 提供基于引文数据的期刊评价指标 显示出引用和被引期刊之间的相互关系 帮助用户以定量的方式了解全球的学术期刊,利用JCR on Web深入了解学术期刊,Calculation of Journal Impact Factor,Example: 2004 Impact Factor for New England Journal of Medicine,2002,2003,2004,366 papers published in 2003,14147 times cited in 2004,378 papers published in 2002,14549 times cited in 2004,378+366,14549+14147,744,28696, 38.570,Journal Citation Reports 2004 Science Edition,Impact Factors only take the recent 3 years into consideration. What about the fields with a longer citation span?,2004 IF =38.570,The journal impact factor is a measure of the frequency with which the “average article“ in a journal has been cited in a particular year. The impact factor will help you evaluate a journals relative importance, especially when you compare it to others in the same field.,Journal Impact Factor,Average citation count in a particular year Assigned at “journal level” Assigned to journals indexed in Citation Indexes SCIE (Science Citation Index Expanded) SSCI (Social Sciences Citation Index) Included in Journal Citation Reports database Updated annually Helpful when evaluating a journals relative importance Not intended to evaluate individual papers/researchers,Why Impact Factor?,Comparison of scholarly journals Journal collection development in a library Decision-making support for article submission by a researcher Editorial policy development by a journal publisherProblems in SIMPLE comparison of citation counts Size (# of articles published in a year) Frequency (# of issues published in a year),Impact Factor: AVERAGE citation count,Web of Science record example,Cited References: Items cited by this article (29 items),Times Cited: How many articles are citing this article (350 articles),Records are counted at journal-level, then included in Journal Citation Reports,Look up journal info in JCR,What you can tell in Journal Citation Reports,Which journals publish most number of articles? Which journals are most cited in particular disciplines? Which journals have “high impact” in particular disciplines? Which journals publish “hot” topics? Journals self-citations Review article rates Cited-citing relationships of journals,JCR is not for evaluating individuals/papers,Recognize skewed nature of citation data,Citation distributions are not normal (the typical bell-shaped curve) Apparent at every level of analysis,Citation distributions are extremely skewed: few papers or people are cited at high frequency, most cited little,67% papers are below the average,Web of Science, search conducted on Sept 28, 2005,Misuse of “Impact Factor”,I first mentioned the idea of an impact factor in 1955. At that time it did not occur to me that impact would one day become the subject of widespread controversy. It has been used constructively to select the best journals for Current Contents and the Science Citation Index, and for library collections. However, it has been misused in many situations, especially in the evaluation of individual researchers.,“The use of JCR and JPI in measuring short and long term journal impact”. Presented by Eugene Garfield at Council of Scientific Editors Annual Meeting held in May 9, 2000. http:/www.garfield.library.upenn.edu/papers/cseimpactfactor05092000.html,Essential Science IndicatorsSM,Essential Science Indicators,ESI lists the top 1% of scientists and institutions, and the top 50% of countries and journals; also provides benchmarks for evaluating individual papers,