Data sources: Web of Science database of Thomson Reuters. 2000-2008.
平均實際引用率 Mean Observed Citation Rate (MOCR) is defined as the ratio of citation count to publication count, here in a three-year citation window.
平均(期刊)理想引用率 Mean Expected Citation Rate (MECR) is a journal-based expected citation indicator. It is defined as the average citation rate of all papers published in the same journal, in the same year, here in a three-year citation window.
主題領域理想引用率 Field Expected Citation Rate (FECR) is a subject-based expected citation indicator. The field-expected citation rate of a paper is defined as the average citation rate of all papers published in the same subject in the same year, here again in a three-year citation window.
理想/主題領域引用比率 The ratio of the two previous indicators (MECR/FECR) expresses whether the unit under study publishes on average in higher (lower) impact journals than expected on the basis of the underlying subject fields.
(根據主題領域)標準化平均引用率 Normalised Mean Citation Rate (NMCR). This indicator is defined as the ratio of the observed and field-based expected citation impact, that is, MOCR to FECR. If subjects are delineated on the basis of the ISI Subject Categories or complete aggregations of those categories, and journals as entities are assigned to those categories are aggregations, the NMCR values calculated for the complete data set, i.e., for the world total, are by definition equal to one. In the present case, most journals are due to the hybrid search strategy only partially covered, that is, the NMCR value of the world total in the field of cardiology will be different from 1.0.
相對引用率 Relative Citation Rate (RCR) is the ratio of MOCR to MECR. Since the lexical component of the search strategy results in a partial coverage of journals in the set of relevant publications, RCR = 1 for the world total will be a consequence of the selective coverage of non-core journals (cf. Gla¨nzel et al. 2003).
去除自我引用的相對引用率 Relative Citation Ratio eXcluding self-citations (RCRX) Author self-citations are removed from both the expected and the observed citation rate