There are a number of different metrics used to measure the impact that a journal, article, or even an author has in scholarly literature. The basis for an impact factor's formula is measuring how many times an article (or journal, or researcher) has been cited over a certain amount of time. For many impact factors, they are owned by a publishing company who disclose the exact formula that they use, making it hard to recreate the formula on your own.
This page should help teach you about different types of impact factor and how to search for them.
While there are many different measurements used to gauge the impact of a journal article, the most widely used one is Impact Factor (sometimes called Journal Impact Factor), which is a proprietary metric owned by Clarivate. In the case of Impact Factor, the formula is how many times the article is cited in their database JCR in the two or four years after publication.
Keep in mind that while CSUF does not subscribe to the databases which can give you an impact factor for articles. It is recommended instead that for your research, to use some of the other metrics mentioned below:
Field-Weighted Citation Impact
Field-Weighted is very similar to Impact Factor, although it is owned by a different company (Elsevier), and searches for the number of citations in their database Scopus in the first three years after publication, in journals weighted by impact and discipline. CSUF does indeed subscribe to Scopus which can provide you an article's CiteScore, among other metrics. For more information, see the box below on how to find impact factors.
As with the article impact factor, this a proprietary metric owned by Clarivate.
CSUF does not subscribe to the databases which can give you an impact factor for journals. It is recommended instead that for your research, to use some of the other metrics mentioned below:
CiteScore, like Field-Weighted citation impact, is owned by Elsevier, and can be obtained using the Scopus database. For more information on how to get a journal's CiteScore, see the Journals tab of the box below.
This is a freely available impact factor that includes the number of times an journal has been cited in the 5 years after publication, also with a weighted list of journals. Many journals' Eigenfactors can be found at the link above.
By incorporating citation behavior in different disciplines into account, SJR can be used to make comparisons between journals in different disciplines. Scimago is another freely available product which can be searched here. It is also indexed in Scopus.
Source-Normalized Impact per Paper (SNIP)
This indicator measures the average citation impact of the publications of a journal. Unlike the well-known journal impact factor, SNIP corrects for differences in citation practices between scientific fields, thereby allowing for more accurate between-field comparisons of citation impact. SNIPS can be obtained from the link above or in the Scopus database.
The most commonly used metric when tracking author impact is the h-index. The h-index tracks research output by counting the total number of publications and the total number of citations to those works, providing a focused snapshot of an individual’s research performance.
Example: If a researcher has 5 papers, each of which has at least 5 citations, their h-index is 5.
An author's h-index can often be obtained through the Scopus database. For more information on how to obtain these, see the box below. Additionally, authors with a Google Scholar profile will also have their h-index available on their Scholar profile page.
Finding an article's Field-Weighted Citation Impact using Scopus:
1. Sign into Scopus.
2. Paste the title of the article into the search bar, click "Search."
3. Click on the appropriate article title.
4. On the next screen, you'll see the metrics available beneath the article title:
5. For more information, click on the "View all metrics" link.
Finding CiteScore, Scimago, and SNIP using the Scopus database:
1. Sign into Scopus.
2. On the next page, click on the Sources link at the top of the page:
3. On the next page, search for your journal by title. Select your journal from the results.
4. On the journal's page, you'll see the CiteScore, Scimago, and SNIP on the right:
H-index in Scopus
1. Sign into Scopus.
2. On the main page, click on the Author's link directly above the search window:
3. Use a combination of names and affiliation to search for the author you are looking for. Conversely, you can always begin by searching for an article by the author and clicking on their name there.
4. The author page will have the h-index listed on the left of the page:
