Understanding Journal Metrics
Quantitative Assessment of Journals
Any research database with citation counts can create research metrics data for journals or individual researchers. When using this data it is important to remember that:
- No source is comprehensive
- Databases only provide analysis of the journals that are indexed in their database
- Many journals do not have an impact factor
- Citation counts are primarily for journal articles and the journals in which they are published
- Journal impact factors can be manipulated
- English language publications may be favoured
Information for New Users
The need to focus on quality publications for research, citing and publishing is continuously emphasized. The systems in place tend to rely on metrics and other pre-defined standards of quality, which can disadvantage some areas.
Factors to consider when determining the most appropriate journals in which to publish your research include:
- Discipline relevance and reaching the desired target audience
- Journal quality or impact, often determined through use of metrics
- Prestige of the editorial team, contributors and journal circulation
Impact Factor vs SJR
The Impact Factor and SCImago Journal Ranking (SJR) are two common measurements or rankings of journal quality. Both measures look at the number of citations the journal has received.
This table highlights some of the main differences and commonalities between the two measures:
| Impact Factor | SJR | |
|---|---|---|
| Source | JCR (Web of Science) | Scopus |
| A measure of... | Citation impact | Prestige |
| Is the ranking publicly available? | No. Subscription access only via JCR | Yes. Available via SCImago website. |
| How many journal titles are included? | ~10,500 | ~18,000 |
| How is the rank calculated? | The number of current year citations to the source items published in that journal during the previous two years | Iterative process based on transfer of prestige from a journal to another, using current year citations to the source items published in that journal during the previous three years |
| What citations are included? | All document types (including editorials) | Articles, conference papers and reviews |
| What documents are included? | Articles and reviews | Articles, conference papers and reviews |
| Can the ranking be used to compare disciplines? | No. You should only compare journal impact factors for the same field | Yes. The rank has been normalised to account for differences between the disciplines |
| Further information | The Impact Factor | About SJR |
| : | Source | |
| Impact Factor: | JCR (Web of Science) | |
| SJR: | Scopus | |
| : | A measure of... | |
| Impact Factor: | Citation impact | |
| SJR: | Prestige | |
| : | Is the ranking publicly available? | |
| Impact Factor: | No. Subscription access only via JCR | |
| SJR: | Yes. Available via SCImago website. | |
| : | How many journal titles are included? | |
| Impact Factor: | ~10,500 | |
| SJR: | ~18,000 | |
| : | How is the rank calculated? | |
| Impact Factor: | The number of current year citations to the source items published in that journal during the previous two years | |
| SJR: | Iterative process based on transfer of prestige from a journal to another, using current year citations to the source items published in that journal during the previous three years | |
| : | What citations are included? | |
| Impact Factor: | All document types (including editorials) | |
| SJR: | Articles, conference papers and reviews | |
| : | What documents are included? | |
| Impact Factor: | Articles and reviews | |
| SJR: | Articles, conference papers and reviews | |
| : | Can the ranking be used to compare disciplines? | |
| Impact Factor: | No. You should only compare journal impact factors for the same field | |
| SJR: | Yes. The rank has been normalised to account for differences between the disciplines | |
| : | Further information | |
| Impact Factor: | The Impact Factor | |
| SJR: | About SJR |
JCR Searches on Video
A complete overview of the Journal Impact Factor metric - learn how it's calculated, and how it's used.
