Journal impact

Journal measures provide a quantitative assessment of a particular journal within its field. The main tools for evaluating journal impact use data from Scopus (SNIP and SJR), Web of Science (Journal Impact Factor and Eigenfactor) and Google Scholar.

Which tool to use depends on where your publications appear as the coverage varies between sources.

Some journals are not covered by the journal measures listed in this guide. While journal measures are useful, their absence does not indicate lack of quality. The quality of a journal can also be assessed by features such as:

  • High standards for acceptance of manuscripts.
  • A broadly representative editorial board.
  • A critical refereeing system.
  • Promptness of publication.
  • Coverage by major abstracting and indexing services.
  • High frequency of citation by other journals.

Consider

  • Journal measures are usually best used for comparisons of journals within the same subject area. A few journal measures such as SNIP factor disciplinary differences into the metric.
  • Metric counts are higher for journals that include lots of review articles.
  • A range of metrics for the same journal, where available, provides a more robust view of a journal's overall impact. Journal rating lists supplement the citation based impact rankings from the Journal Citation Reports and Scopus metrics.
  • A journal impact metric should not be used as a surrogate for the citation impact of an individual publication, or the citation impact of the set of publications from an individual or a research group.

The Journal Impact Factor is a measure of the frequency with which the "average article" in a journal has been cited in a particular year or period. Journal Impact Factors apply to journals listed in the database Journal Citation Reports. It is a well-established metric, widely used by researchers in the sciences as a proxy measure of journal quality.

Read more about Journal Impact Factor.

Includes

  • Many journals in the science and medical sciences.
  • Good coverage of some engineering and social science disciplines.

Use

  • The two-year window for fast moving research fields such as basic sciences, rather than clinical medicine or public health.
  • The five-year window for clinical medicine or public health.
  • To establish how frequently a journal is being cited. Averaging over the total number of published and citable items of a journal tends to discount the advantage of large journals over small ones and of frequently issued journals over less frequently issued ones.

Do not use for

  • Comparing journals from different disciplines. The journal impact factor does not take account of differing citation practices between fields of research.

Consider

  • Smaller, more specialised journals tend to have lower Impact Factors.

Eigenfactor metrics apply to journals indexed in the database Web of Science and listed in the Journal Citation Reports database. It uses a five-year citation window. The Eigenfactor algorithm is a prestige metric which reflects the idea that journals are considered to be influential if they are cited often by other influential journals.

Read more about Eigenfactor.

Includes

  • Comprehensive coverage for journals in the sciences and medical sciences.
  • Primarily English-language journals.
  • Journals published in North America.
  • Moderate coverage for journals in the social sciences.

Excludes

  • Journal self-citations.

Use for

  • Disciplines with a longer timeframe for citations to be generated.
  • Estimating the amount of time scholars spend reading a journal, and thus its overall influence.

Do not use for

  • Replicability, as the calculation is complex.

Consider

  • The type of publication is not taken into account.
  • Increases when a journal is cited more often in highly-cited journals.
  • Increases when a journal publishes more articles in one issue.

CiteScore is an impact factor based on a three-year citation window, calculated using data from the Scopus database and is updated once a year. It is the number of citations to a journal in one year to documents published in the three previous years, divided by the number of documents included in Scopus published in those same three years.

Read more about Scopus: CiteScore.

Includes and excludes

  • CiteScore's numerator and denominator both include all document types (unlike the original two and five-year impact factors which only include articles in their denominator).
  • Excludes articles in press.

Benefits

  • The three-year window is the best compromise for this broad-scope database. It incorporates a representative proportion of citations in all disciplines, while also reflecting relatively recent data.

Do not use for

  • Comparing journals between subject fields.
  • CiteScore is not subject field-normalised, and different publications and citation behaviour of researchers in different fields affects the values, as well as differences in performance. Use Citation Percentile instead.

Consider

  • CiteScore Tracker, calculated in the same way as CiteScore, but for the current year rather than previous, complete years.
    The CiteScore Tracker calculation is updated every month, as a current indication of a title's performance.

Source Normalized Impact per Paper (SNIP) measures apply to journals indexed in the database Scopus and are updated once a year.

Read more about SNIP.

SNIP defines a subject field as the collection of articles citing the journal. It factors in

  • A subject field’s citation immediacy (how often recent publications are cited).
  • How well the field is covered by Scopus.
  • Adjusts for differences in citation patterns among disciplines, to ensure that journals in subjects with low citation frequency are not disadvantaged.

Includes

  • Journal articles, reviews and conference papers.
  • Peer-reviewed journals.
  • Journal self citations.
  • English-language journals.

Takes into account

  • How often recent publications are cited (immediacy).
  • Scopus coverage for the discipline the journal covers.

Use for

  • Multi-disciplinary journals - SNIP defines a subject field as the collection of articles citing the journal.
  • Replicability.
  • Comparison across disciplines - SNIP corrects for differences between citation practices across disciplines.

Do not use for

  • Assessing the growth of the literature in a field nor the extent to which papers in a field are cited from other fields.
  • Journals with a small number of publications per issue.

SciMago Journal Rank (SJR) metrics apply to journals indexed in the database Scopus from 1996 onwards using a three-year citation window and are updated once a year.

The SJR reflects a journal’s prestige. Citations are weighted, and the metric takes into account - the subject field, quality and reputation of the journal.

It is a size-independent indicator, ranking journals by their "average prestige per article" and can be used for journal comparisons.

Read more about SJR.

  • SJR Open Access Portal
    The SCImago Journal & Country Rank (SJR) open access portal provides journal rankings based on Scopus data. It has better coverage of humanities and social sciences than other tools, allows for comparisons across disciplines and contains over 100 New Zealand journals.

Google Scholar journal metrics are available for the last five years.

Includes

  • Journal self citations.
  • Comprehensive geographical spread of journals.
  • English-language journals.
  • Journals in many different languages.
  • Good coverage of journals in the non-STEM disciplines (arts, humanities and social sciences.)

Use for

  • Comparisons by thematic area and discipline limited to journals in English.
  • Indexes journals from more countries in more languages.
  • Better coverage of journals in arts, humanities and social sciences.

Consider

  • Cannot replicate.
  • A journal's lifetime h-index will never decrease. Once a journal publishes twelve papers with 12+ citations, no matter how many more papers are published, the h-index can only increase.

Journal rating lists supplement the citation based impact rankings from the Journal Citation Reports and Scopus metrics. Many lists are collated by experts in a field and are specific to a particular discipline.

Some of the major lists are below, contact your Subject Librarian to find out if there are any rating lists specific to your discipline.

Multidisciplinary

Excellence in Research for Australia (ERA) Journal lists - 2015
The Rating Lists used in the Excellence in Research for Australia (ERA) research assessment exercise are one of the most well known. Multidisciplinary coverage from Humanities and Creative Arts through to Medical and Health Sciences.
Note: the 2010 journal list provided rankings. These rankings are no longer available.

Arts and Humanities

European Reference Index for the Humanities and the Social Sciences (ERIH Plus)
An index produced by the European Science Foundation and developed by expert panels of European researchers. The ERIH covers publications in the humanities and social sciences including those published in European languages. Coverage of over 14 disciplines including Anthropology, History and Philosophy.

Business and Economics

The Australian Business Deans Council Journal Quality List (ABDC)
The ABDC list was reviewed in 2016 and covers the Business, Economics and Law disciplines. The list is based on citation metrics, subject area experts and other journal quality lists. Journals are ranked in A, B or C categories.


Last updated : 12 April 2018
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