ดัชนีชี้วัดคุณภาพวารสาร (Journal Metrics)

Database
Indicator
Meaning
Web of Science Impact Factor An average number of citations for articles published in the last two years (starting with the Journal Citation Reports (JCR) year). It is calculated by dividing the number of citations by the total number of articles in the previous two years. Example: Impact factor value of Journal A is 2.5, which means the average number of citations per article in the last two years is 2.5.
5-Year Impact Factor An average number of citations of articles published in the last five years (starting from the year of Journal Citation Reports (JCR). It is calculated by dividing the number of citations by the total number of articles in the previous five years. It is appropriate to check journal quality that some fields have a citation value in a long-term increase; for example, Journal of Geology, Journal of Sociology, etc.
Eigenfactor The total number of citations after publication of articles in the previous five years, weighted by the reputation of the journal. Namely, highly cited journals will have higher scores than lesser cited journals. Eigenfactor are scaled to 100 from all journals listed in JCR database. * For JCR database, PLoS One Journal has the highest Eigenfactor scores, 1.38933 (information as of 10th Jun. 2021)*
Immediacy Index An indicator measures how quickly articles in a journal are cited calculated by the total number of citations divided by the number of articles published by the journal in that year. Immediacy Index an article published early in the year has a better chance of high index scores than the one published later in the year because of cutting points at the end of every years.
Scopus CiteScore The average number of citations to an article in the previous four years, calculated by dividing the total number of citations by the total number of articles published in those four years; for example, CiteScore of Internet and Higher Education Journal is 17.1 , meaning that it has been cited 17 times approximately in four years.
SNIP Article citation averages weighted by “field” because each field has different popularity and number of students. Researchers will have an accurate comparison of the average number of article citations.
SJR The average number of article citations is weighed by ‘subject field’ same as SNIP, but journal prestige is added to weight scores because high-prestige journals are more likely to be accessed than lower-prestige journals. Researchers will have an accurate comparison of the average number of article citations.
* SNIP and SJR are calculated from the scores in the past three years. The standard ratio is 1.00 (if the value is more than 1.00, which means the average number of citations is higher than the standard comparing with other journals in the same field and the same time period (3 years), or, if the citation value is less than 1.00, which means the average number of citations is less than the standard.
Web of Science, Google Scholar, or Scopus H-index The index measures the productivity and impact of researches. The high index value is up to the high number of articles and citations. H-index will tell us the number of articles which citation is less or equal the number of works. (For example, H-index value of Journal A is 15, which means works in Journal A are 15, and each work is cited 15 times). Remark: Because each database has a different citation data, H-index value may also be different.
(Any source) Altmetrics Newly alternative measurement improved from the old set (citation / H-index, Impact Factor value, Impact factor). Indicators added are hitting Like, Tweet, Share, comments, bookmark, recording, views, and download time.

Ref: https://authorservices.wiley.com/author-resources/Journal-Authors/find-a-journal/journal-metrics.html