مقایسهٔ روش‌ها

	Garfield's Law of Concentration	Relative Specialization / Activity Index
حوزه	کتاب‌سنجی	کتاب‌سنجی
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1972	1986
پدیدآور	Eugene Garfield	J. Davidson Frame (activity index); András Schubert & Tibor Braun (relative indicators)
نوع	Descriptive bibliometric law and core-journal identification pipeline	Normalized bibliometric indicator of revealed research specialization
منبع بنیادین	Garfield, E. (1972). Citation analysis as a tool in journal evaluation. Science, 178(4060), 471-479.	Schubert, A., & Braun, T. (1986). Relative indicators and relational charts for comparative assessment of publication output and citation impact. Scientometrics, 9(5-6), 281-291.
نام‌های دیگر	Law of Concentration, Core Journal Concentration, Garfield Concentration Law	Activity Index, Relative Specialization Index, Revealed Comparative Advantage in Science, Attractivity Index
مرتبط	3	3
خلاصه	Garfield's Law of Concentration is the bibliometric principle that the bulk of the significant scientific literature is concentrated in a relatively small, largely multidisciplinary core of journals. Formulated by Eugene Garfield — founder of the Science Citation Index — and presented in his 1972 Science paper 'Citation analysis as a tool in journal evaluation', the law observes that when journals are ranked by how often they are cited, a core of perhaps 500 to 1,000 journals accounts for the overwhelming majority of all citations across all fields. Garfield framed it as a generalization and corollary of Bradford's earlier law of scattering: the long tail of any one discipline's literature is in large part composed of the cores of other disciplines, so a single multidisciplinary core covers science as a whole. The law underpins the rationale for selective, citation-based journal indexing.	The Relative Specialization Index and the closely related Activity Index measure how much a country, institution, or other unit concentrates its research effort in a given field relative to a global benchmark. The Activity Index, popularized by J. Davidson Frame in the 1970s, compares a unit's share of its own output devoted to a field against the world's share of output in that field: a value above 1 means the unit is more active (more specialized) in that field than the world average, and below 1 means less. András Schubert and Tibor Braun's relative-indicator framework formalized this family and introduced bounded, symmetric variants and 'relational charts' that pair publication activity with citation 'attractivity'. These indices are the scientometric analogue of revealed comparative advantage in trade and are central to national and institutional research-profiling.