Journal Impact and Evaluation
Journal impact metrics attempt to quantify the importance of a particular journal in a field. They take into account the number of articles published per year and the number of citations to articles published in a particular journal. These metrics are one factor to consider when deciding on where to publish. Like author impact measurements, journal impact metrics have limitations and no single measure gives a complete assessment. Researchers will have the best sense of the top journals in their field.
Below are some of the more common metrics and evaluation tools used to evaluate and measure a journal’s impact.
| Impact Factor (IF) | Eigenfactor | SCImago Journal Ranking (SJR) | Source Normalized Impact per Paper | |
| Measure of... | Frequency with which the 'average article' in a journal has been cited in a particular year or other defined time period | Measure of importance: overall value provided by all articles published in a journal in one year | Measure of prestige; accounts for number of citations received by a journal and importance of the journals that citations came from | Measures citation impact by weighting citations based on the total number of citations in a subject field |
| Calculation | A: Number of citations in the current year to items published in the journal in the previous two years B: Total number of articles published in the journal in the previous two years Impact Factor = A/B | Citations from high-quality journals are weighted more than citations from lesser known journals
| Citations from more prestigious journals (higher SJR) weighted more than citations from less prestigious journals (lower SJR) | More weight is given to citations from subject areas where citations are less likely. |
| Can it be used to compare journals from different disciplines? | No | Yes | Yes | Yes |
| Where can I get it? | Journal Citation Reports (provided by NC State University Libraries) | Journal Citation Reports OR free from Eigenfactor.org | Scopus (subscription required) OR free from SCImago Journal & Country Rank | Scopus |
| This table is taken from the University of North Carolina at Chapel Hill Health Sciences Library's research impact guide |
For more information or assistance, email the Library Impact Metrics team