"Get deep Once" SCI and jcr--journal a method of influencing factor (IF) and frequency of reference (CI) calculation in one year

Http://lib.hebust.edu.cn/xxjy/sci/SciEi.htm the JCR Journal of the Chinese Academy of Sciences is a partition of all periodicals in the corresponding annual Journal Citation report (JOURNAL citation REPORTS,JCR). The JCR Periodical partition table includes the large class partition table and the small type partition table, the large class partition table is the partition which the periodical is made according to the 13 relatively coarse subject category, and the small type partition table is the partition which the periodical is made by the 176 comparatively fine subjects which are provided by the JCR. JCR Journal partition data has been published since 2004 and continues to date, updated annually in September-November. |· Introduction to SCI and JCR |

SCI ("Science Citation Index", English is all called Science Citation Index) is the American Institute of Scientific Information (Institute for scientific information, referred to as ISI, website:/http www.isinet.com/) published a world-renowned search tool for periodical literature, published in the form of printed periodicals and CD-ROM and online databases, and now publishes Web databases on the Internet.

The SCI contains about 3500 core periodicals of various sciences, such as number, rationale, chemistry, Agriculture, forestry, medicine, life sciences, astronomy, geography, environment, materials, engineering technology, etc. Through its rigorous offprint standards and assessment procedures, ISI selects the source, and the annual increase or decrease, so that the literature included in the SCI can comprehensively cover the world's most important and most influential research results.

The so-called most influential findings of the ISI refer to the literature that has been reported on these results in large numbers by other references. To this end, as a search tool, SCI Anti-other search tools through the topic or classification approach to retrieve the general practice of literature, and set up a unique "citation Index" (citation). That is to illustrate the relevance of the literature and the influence of the previous literature on the current literature through the reference of the current literature.

The characteristics of the above methods make sci not only be used as a document retrieval tool, but also become a basis for scientific research evaluation. Scientific research institutions are included in the total amount of paper, reflecting the entire organization of scientific research, especially the level of basic research, the number of individual papers collected by SCI and cited times, reflecting his research ability and academic level.

In addition, the ISI publishes JCR annually (the Journal Citation Report, full name Journal Citation Reports). JCR the citation and quoted data of 4700 periodicals, including the 3500 periodicals included in the SCI, to be counted and calculated, and reported on indexes such as impact factors (impacts Factor) defined for each journal. A thesis author can decide the direction of submission according to the influence factor ranking of periodicals. |· JCR Professional noun Introduction and important parameter Calculation |

(i) JCR commonly used words explained

Citation: citations, reference documents;   Citing: citation;   Cited: be quoted; CITES: Number of references (citations)

(ii) Methods for calculating the JCR indices

Four indices, such as "Impact Factor", "Immediacy Index", "cited Half life" and "citing half", are defined in JCR, and the following calculations are based on the 1996 science        Magazine as an example to explain the calculation methods of various indices. Brief introduction of periodical partitioning method: The influential factors of sci-tech periodicals (if,impact Factor) and the total cited frequency (CI) can reflect the display degree of periodicals from different angles: IF can measure the frequency of the periodicals in the last two years;1. Impact Factor Influence Factor(IF): 23.605
IF = (C2 + C3)/(A2 + A3)
Among them, A2 = number of documents published in 1995 = 1037 (article)
A3 = Number of documents published in 1994 = 1054 (article)
C2 = number of citations published in 1995 = 24189 (Times)
C3 = number of citations published in 1994 = 25170 (Times)
IF = (24189 + 25170)/(1037 + 1054) = 23.605 (Times/chapter) CI can measure the display level of periodicals in academic circles from the perspective of historical development. In addition, the main theoretical basis of this method is Bradford's law of documentary concentration. The law of Bradford is embodied in the distribution of the periodical influence factor and the cited frequency, and the relatively high influence factor and the frequency of the citation are concentrated in a few periodicals.2. Immediacy Index timeliness(IX): 4.837
IX = C1/A1
Among them, A1 = number of documents published in 1996 = 1095 (article)
C1 = number of citations published in 1996 =5297 (Times)
IX = 5297/1095 = 4.837 (Times/article) Therefore, the JCR periodical division is based on the impact factor and the frequency of two indicators, using the ISI published Journal Citation REPORTS (JCR) data in the results obtained. Secondly, I would like to correct some people's understanding of the impact factor calculation of the error, Impact factor if Factor is based on the first 2 years (not 1 years) calculated, that is, the paper published in the previous 2 years in the statistics of the total number of citations in the year except the previous 2 years of the total number of papers published. Give us a simple example--for example: the calculation of the impact factor for a periodical in 2012---------the number of times that the journal's 2010 articles were cited in 2012:---------the number of articles in the journal 2011 that were cited in 2012:------ ---the publication volume of the Journal for 2010 years:---------The number of posts in the journal for 2011 Years: 2012 if= (40+15)/(50+50) =0.55 of the journal in the year of---------;--------- The last 2012 years of the journal if is 0.55.