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Fee-based database accessible at
http://www.isiknowledge.com/JCR

Journal Citation Reports (JCR) was first published in 1975. Since then it has been published annually by Thomson Reuters previously known as The Institute for Scientific Information (ISI).
JCR is a comprehensive and unique resource that allows the evaluation and comparison of journals using citation data drawn from over 7,500 scholarly and technical journals included in the Web of Science -database. It presents quantifiable statistical data that provides a systematic, objective way to evaluate the world's leading journals and their impact and influence in global research community. Researchers can use JCR to identify journals in which to publish, confirm the status of journals in which they have published, and identify journals relevant to their research. JCR shows the most frequently cited journals in a field, the highest impact journals in a field, and the largest journals in a field.

JCR is published in two editions:

  • JCR Science Edition contains data from over 8 000 journals in science and technology.
  • JCR Social Sciences contains data from almost 3 000 journals in the social sciences.
    The two editions overlap of about 10%.

JCR is comprehensive but not all-inclusive in journal coverage. It aims to cover the core of the world's most important peer-reviewed journals. The core of journals is not static, but changes constantly reflecting the evolution of scholarly topics, and the journal coverage of Web of Science -database is updated accordingly.

The Thomson Reuters journal selection process is available at http://www.thomsonreuters.com/products_services/science/free/essays/journal_selection_process/.

Each journal indexed in JCR is assigned to at least one subject category, indicating a general area of science or the social sciences. Journals may be included in more than one subject category; therefore, when comparing journals across related categories, it is possible to see the same journal title in different categories. Some of the journals listed in JCR are not citing journals, but are cited-only journals. This means that the references in these journals are not included in the database. This is significant when comparing journals because self-citations from cited-only journals are not included in JCR data. Self-citations often represent a significant percentage of the citations that a journal receives. Cited-only journals may be ceased journals, suspended journals, or superseded titles. Any journal that appears elsewhere in JCR, but not in the Citing Journal Listing, is a cited-only journal.

Several new features are included in the 2007 JCR:

  • Eigenfactor and Article Influence metrics
  • Five-year Impact Factor scores
  • Analysis of journal self-citations
  • Impact Factor box plots
  • Rank-in-category tables for journals covering multiple disciplines

Indicators

For further details see 1.3.1.7.13 Citation metrics.

Journal Impact Factor (IF)

The main indicator of JCR. The impact factor of a journal represents the average citation count of the articles published in the journal during a two-year period. It provides a way to evaluate a journal's relative importance to others in the same field. The IF has been extensively used in the past decades as an instrument for the evaluation of quality of scientific journals, it has not been spared from criticism. The main points of criticism are the lack of assessment of the quality of citations, the inclusion of self-citations, the poor comparability between different scientific fields, and the analysis of mainly English-language journals.

5-year Impact Factor

The 5-year Impact Factor is available only in JCR 2007 and later. The 5-year journal Impact Factor is the average number of times articles from the journal published in the past five years have been cited in the JCR year. It is caclulated by dividing the number of citations in the JCR year by the total number of articles published in the five previous years.

Journal Immediacy Index

Immediacy Index measures how often articles published in a journal are cited within the same year. It is useful in comparing journals specialising in cutting-edge research.

Eigenfactor (EF)

Eigenfactor is available only for JCR years 2007 and later. The Eigenfactor Score measures the number of times articles from the journal published in the past five years have been cited in the JCR year.
Like the Impact Factor, the Eigenfactor Score is essentially a ratio of number of citations to total number of articles. However, unlike the Impact Factor, the Eigenfactor Score counts citations to journals in both the sciences and social sciences, eliminates self-citations, and weights each reference according to a stochastic measure of the amount of time researchers spend reading the journal.

Article Influence (AI)

Article Influence is available only for JCR years 2007 and later. It measures the relative importance of the journal on a per-article basis. It is the journal's Eigenfactor Score divided by the fraction of articles published by the journal. That fraction is normalized so that the sum total of articles from all journals is 1. The mean Article Influence Score is 1.00. A score greater than 1.00 indicates that each article in the journal has above-average influence. A score less than 1.00 indicates that each article in the journal has below-average influence.

Other indicators

Other indicators include Total number of Articles (includes original and review articles), Total citations (the total number of times a journal has been cited by all journals included in the database, including self-citations), Journal cited half-life (The number of publication years from the JCR edition year, which account for 50% of citations received in the JCR edition year. The figure gives the age of cited articles of a journal.), and Journal citing half-life (The number of publication years from the JCR edition year that account for 50% of citations in the JCR year published by a journal in its article references. The figure gives the age of the majority of articles referenced by a journal.).

Evaluation of journals

Journals can be evaluated at the journal level, journal category level, and at all journals level.


On the first screen, the wellcome-page, you will select the JCR edition you wish to search and the year. You also select which type of search you want to run: view a group of journals (by Subject Category, Publisher or Country), search for a specific journal or view all journals in the JCR edition and year selected.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.


A functionality flow graph for JCR.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 19.8.2009.


Individual journals

Searching for a specific journal is possible by full journal title, journal abbreviation, title word, or ISSN.




Journal data for Genome Research in 2010 JCR Science edition.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Impact Factor trend graph for Genome research, which gives Impact Factor values for five preceding years.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Clicking on the journal title gives the full record of the journal, which includes journal title abbreviations, publisher, and JCR subject categories of the journal. The Eigenfactor Metrics are available in 2007 JCR edition and later.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Cited Journal Graph shows the distribution by cited year of citations to articles published in a journal. The white/grey division indicates the approximate position of the cited half-life. The top (gold or yellow) portion of each column indicates journal self-citations. The bottom (dark blue) portion of each column indicates non-self citations. The two light blue columns indicate citations used to calculate the Impact Factor.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Citing Journal Graph shows the distribution by cited year of citations from articles in the selected journal. All of the citing articles were published in the JCR edition year. The white/grey division indicates the approximate position of the cited half-life. The top (gold or yellow) portion of each column indicates journal self-citations. The bottom (dark blue) portion of each column indicates non-self citations.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Cited Journal Table lists the journals that cite the source journal in the year chosen. In the table, the cited journal is Genome Research, and all the citing articles are published in 2010.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Citing Journal Table lists journals cited by the source journal in the year chosen. In the table, the citing journal is Genome Research, and all of the citing articles were published in 2010.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Journal Self Cites link gives the Self-Citation rates of a journal, and also Impact Factor calculated without Self-Citations.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Related Journals have cited and citing relationships with the source journal. Two values are given in the Relatedness column: Citations from source journal to Related Journal, and Citations from Related Journal to source journal. The higher of these two values appears in the Rmax column. Journals in the table are ranked according to the Rmax value. The table gives Related Journals for Genome Research.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Journal Ranking table shows the ranking of the current journal in its subject categories based on the journal Impact Factor. The table gives Rank in Category data for Genome Research in three subject categories.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The category box plot is the Impact Factor box plot for the subject category to which the journal belongs. The horizontal line that forms the top of the box is the 75th percentile. The horizontal line that forms the bottom is the 25th percentile. The horizontal line that intersects the box is the median Impact Factor for the category. The cross represents the mean value. Horizontal lines above and below the box represent maximum and minimum values that are no more than 1.5 times the span of the interquartile range, which is the range of values between the 25th and the 75th percentiles. These lines are commonly referred to as "whiskers." An open circle represents an outlier, which is a single value greater or less than the extremes indicated by the whiskers. The example shows category box plots for Genome Research. The subject categories are: A: Biochemistry & Molecular Biology, B: Biotechnology & applied microbiology, and C: Genetics & Heredity.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.


Group of journals

The group of journals can be selected by subject category, publisher, or country or territory. If more than one subject category group is selected, the results can be sorted by Category Title, Total Cites, Median Impact Factor, Aggregate Impact Factor, Aggregate Immediacy Index, Aggregate Cited Half-Life, Number of Journals, and Total Number of Articles.



Subject Category Summary list for categories Biochemistry & molecular biology and Biotechnology & Applied microbiology sorted by Median Impact Factor. View Journal Summary List -button gives journal information for journals belonging to the categories selected.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Category information for subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Journal Summary List for subject categories Biochemistry & molecular biology and Biotechnology & Applied Microbiology sorted by Impact Factor.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Aggregate Cited Category Graph shows the distribution by cited year of citations to articles published in journals in the category in the JCR edition year. The white/grey division indicates the cited half-life.The light-blue columns indicate citations used to calculate the Impact Factor. The example shows the Aggregate Cited Category Graph for subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The Citing Category Graph shows the distribution by cited year of citations from journals in the category made in the JCR edition year. The white/grey division indicates the citing half-life. The example shows the Aggregate Citing Category Graph for subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.





The Related Journals -button gives the relatedness of journals to a subject category. Related Journals have cited and citing relationships with the source journal. Two values are given in the Relatedness column: Citations from source journal to Related Journal, and Citations from Related Journal to source journal. The higher of these two values appears in the Rmax column. Journals in the table are ranked according to the Rmax value. The example shows related journals to subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




Frequency of publication data categorize the journals in the subject category according to their publication schedule. The example shows publication frequency data for subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.




The category box plot shows the distribution of Impact Factors for the subject category. The horizontal line that forms the top of the box is the 75th percentile. The horizontal line that forms the bottom is the 25th percentile. The horizontal line that intersects the box is the median Impact Factor for the category. The cross represents the mean value. Horizontal lines above and below the box represent maximum and minimum values that are no more than 1.5 times the span of the interquartile range, which is the range of values between the 25th and the 75th percentiles. These lines are commonly referred to as "whiskers." An open circle represents an outlier, which is a single value greater or less than the extremes indicated by the whiskers. The example shows the category box plot for subject category Biochemistry & Molecular Biology.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.


All journals

View all journals selection on the welcome-page gives a list of all the journals for the year and JCR edition selected. The results can be sorted by Journal Title, Total Cites, Impact Factor, Immediacy Index, Current Articles, Cited Half-Life, 5-year Impact Factor, Eigenfactor, and Article Influence.



All journals for 2010 JCR Science edition sorted by Impact Factor.
Source: Journal Citation Reports (Thomson Reuters) <http://www.isiknowledge.com/JCR> 29.6.2011.