How do bibliometrics work?

There are different bibliometrics, which work in different ways. Here are some of the most common:

Citation count   

Usually used in relation to journal articles, this simply involves counting how many citations the article has received. The more citations an article has, the greater value and impact it is deemed to have.

H-index

This is used to assess authors' productivity and impact. It looks at how many publications authors have and how many citations those publications have received. For example, if an author has an h-index of 20, it means they have 20 publications that have received 20 citations or more.

Journal Impact Factor

Used to compare journals, this is a metric owned by Thomson Reuters and applied to titles in their Web of Knowledge database. It is based on the average number of citations received by recent articles published in a particular journal.

SCImago Journal Rank (SJR)

Measures a journal's impact by looking at the number of citations its articles get over a two year period and the prestige of the journals from which these citations come, among other factors. Owned by Elsevier and based on data from their Scopus database.