手法を比較

	ジャーナルインパクトファクター	h-index（エイチインデックス）
分野	計量書誌学	計量書誌学
系統	Process / pipeline	Process / pipeline
提唱年	1955	2005
提唱者	Eugene Garfield, Institute for Scientific Information (ISI)	Jorge Hirsch, University of California San Diego
種類	Metric	Metric
原典	Garfield, E. (1972). Citation analysis as a tool in journal evaluation. Science, 178(4060), 471-479.	Hirsch, J. E. (2005). An index to quantify an individual's scientific research output. Proceedings of the National Academy of Sciences USA, 102(46), 16569-16572.
別名	IF, JIF, Impact Factor, 2-year Impact Factor	Hirsch index, h factor, h-number
関連	5	5
概要	Journal Impact Factor (JIF) is a metric developed by Eugene Garfield in 1955 and published annually by Clarivate Analytics through Journal Citation Reports (JCR). It measures the average citation frequency of articles published in a journal over a two-year window, serving as a proxy for journal prestige and influence. A journal's Impact Factor equals the number of citations received in year Y to articles published in Y-1 and Y-2, divided by the number of citable items published in that same window. Despite widespread adoption in research evaluation, Impact Factor has significant limitations and critics argue it conflates journal prestige with article quality.	The h-index, or Hirsch index, is a quantitative metric proposed by physicist Jorge Hirsch in 2005 to measure researcher productivity and citation impact simultaneously. A researcher has an h-index of h if they have published at least h papers, each cited at least h times. For example, an h-index of 20 means the researcher has 20 papers each cited at least 20 times. The h-index is widely used in research evaluation, hiring, and promotion decisions, though experts debate its limitations. It provides a single number balancing quantity of publications against quality of citations, offering an intuitive summary of research career impact.