Impact and metrics
We are a signatory to the San Francisco Declaration on Research Assessment (DORA) and believe that while metrics form part of a holistic assessment of research, no metric should be used in isolation to assess the value and impact of research. To this end we have created this page to show a range of metrics about our journals, as well as providing article-level metrics for every article. We hope in this way to allow assessment of the impact of individual articles as well as the journals in which they are published.
Article-level metrics
Article usage statistics are updated for each article monthly and can be found within the ‘Metrics’ tab in the 'Info' dropdown menu for each article; Altmetrics appear in the same location but are updated daily. This section provides a journal-level summary of these article metrics using 2021 data: full-text download information is based on platform usage statistics, while Altmetric data is from the Altmetric Explorer.
| Metric | Microbiology | Journal of General Virology | Journal of Medical Microbiology | International Journal of Systematic and Evolutionary Microbiology | Microbial Genomics | Access Microbiology |
|---|---|---|---|---|---|---|
| Unique full-text downloads | 2,493,465 | 1,796,487 | 1,415,717 | 5,748,629 | 1,045,750 | 573,610 |
| Mean Altmetric score | 10.9 | 7.7 | 9.8 | 4.8 | 18.6 | 3.9 |
| Median Altmetric score | 4 | 3 | 5 | 2 | 5 | 2 |
Journal-level metrics
The data in this section reflects the annual Journal Citation Reports (JCR) from Clarivate Analytics. The section on Definitions below outlines the meaning of each metric.
| Metric | Microbiology | Journal of General Virology | Journal of Medical Microbiology | International Journal of Systematic and Evolutionary Microbiology | Microbial Genomics |
|---|---|---|---|---|---|
| 2-year Journal Impact Factor | 2.8 | 3.8 | 3.0 | 2.8 | 3.9 |
| 5-year Journal Impact Factor | 2.7 | 3.8 | 2.7 | 2.5 | 5.2 |
| Immediacy Index | 0.9 | 1.6 | 0.5 | 0.5 | 1.1 |
| Cited half-life | 15.1 years | 13.9 years | 10.7 years | 9.0 years | 3.7 years |
| CiteScore | 5.0 | 7.9 | 5.2 | 4.5 | 6.0 |
| SNIP | 0.83 | 1.08 | 0.84 | 0.86 | 1.04 |
Definitions
- 2-year Journal Impact Factor: The Journal Impact Factor is defined as all citations to the journal in the current JCR year to items published in the previous two years, divided by the total number of scholarly items (these comprise articles, reviews, and proceedings papers) published in the journal in the previous two years.
- 5-year Impact Factor: 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 calculated by dividing the number of citations in the JCR year by the total number of articles published in the five previous years.
- Immediacy Index: The Immediacy Index is the average number of times an article is cited in the year it is published.
- Cited half-life: The median age of the articles that were cited in the JCR year. Half of a journal's cited articles were published more recently than the cited half-life.
- CiteScore: CiteScore measures average citations received per document published in the serial.
- SNIP (Source Normalized Impact per Paper): The SNIP measures actual citations received relative to citations expected for the serial’s subject field.
- Altmetrics: Altmetrics are non-traditional metrics proposed as an alternative to citation impact metrics. A paper’s Altmetric score is a weighted measure of its mentions in the press and on social media, among others, and is displayed on each article page.