2. representativeness. Papers in a group of core journals of a certain discipline represent the latest level and development direction of the discipline. This feature is determined by the centralization of core journals.
Because a number of core journals concentrate most of the high-quality papers of a certain discipline, they naturally represent the research level and development direction of the discipline, and every progress in discipline research is basically reflected in the papers published in these core journals first.
Extended data:
origin
193 1 Bradford, a famous philologist, first revealed the law of concentration and dispersion of documents, and found that 1/3 papers of a certain discipline were published in 3.2% journals in a certain period; From 65438 to 0967, UNESCO studied the distribution of secondary literature in periodicals and found that 75% of the literature appeared in 10% of the periodicals.
197 1 year, Garfield, the founder of SCI, counted the distribution of references in journals and found that 24% of the citations appeared in 1.25% of journals, and so on. All these studies show that there is a "core effect" in journals, which leads to the concept of "core journals".
According to Bradford's law, if the number of papers published by sci-tech journals in a certain discipline is equal to the number of papers in each district, the number of journals in the core area is 1: n ∧ 2: n ∧ 3: n ∧ 4 ... that is, those journals that publish more papers related to a certain discipline or specialty.