High impact journals

• What is a high impact journal?
  • Using JCR wisely
• Finding journal impact factors
  • Cited-half life
  • Immediacy index
  • Related journals
  • Source data table
• High impact journals and publishing
• JCR search tips

What is a high impact journal?

The impact factor is a measure of the frequency with which the average article in a journal has been cited in a particular year.

ISI Journal Citation Reports (JCR) display the journal impact factor for specific subject areas as a method to rank journals. It is a value that uses the citation counts from ISI Web of Science and is calculated by dividing the number of citations in the current year to articles published in the previous two years by the total number of articles published in the two previous years.

Using JCR wisely

JCR compares journals within specific subject fields using citation data from over 5,900 journals in science and technology and data from over 1,700 journals in the social sciences. However, "citation data are not meant to replace informed peer review."
Many variables influence a journal's impact factor:

• article type, for example journals with a high number of review articles may have a greater impact factor
• changes in journal size, when an article count falls the impact factor may increase temporarily
• titles changes, JCR requires 2 years of data to calculate an impact factor

[JCR Homepage, accessed 5th April 2006]

It is important NOT to compare impact factors across subject areas.

For more information about the strengths and limitations of journal impact factors read UOW Discussion Paper no. 6: Indicators of Journal Quality.

Finding journal impact factors

Use Journal Citation Reports (JCR).

Coverage:

• Year: 2001 - present
• Subject areas: Science and Social Sciences.

Selective Arts and Humanities areas are covered by the Social Sciences index, for example, History and Family Studies.

In addition to the impact factor, JCR also identifies the cited half-life, immediacy index and related journals as well as providing a source data table.

Cited half-life

Represents the median age of the articles that were cited in the JCR year. Consequently a research journal may have a longer half-life than a journal that provides current information such as in the computer sciences.

Immediacy index

Represents the average number of times an article is cited in the year it is published. This may provide a useful perspective for researchers in cutting edge experimentations to identify how quickly areas are cited.

Related journals

This information identifies journals which have a subject relationship with the object journal based on citations either given or received. They are ranked by their degree of relatedness. This list can be used to identify journals that are dependent upon one another, but which may be classified in different subject categories.

Source data table

The table identifies the number of review articles and research articles published by the journal and includes the number of references cited by the articles.

High impact journals and publishing

Identification of high impact journals is important when considering in which journal to publish. A journal with the highest impact factor is more widely read.

The Where do I publish? guide includes JCR and other tools to identify peer reviewed journals.

Searching JCR

1. use the Library guide
2. try ISI JCR tutorial

Last reviewed: 7 November, 2007