Journal, article, and author-level metrics can help tell the story of your work's reach and impact, but there is a growing movement to better understand how metrics have historically been misused and to work toward responsible metric usage. The Metrics Toolkit can help you identify when to use different metrics.
Journal Impact Factor: Calculated by dividing the number of times an article in that journal was cited by the number of articles that were published by that journal in the last two years. Originally used to inform library purchasing decisions, many researchers consider this a (controversial) measure of journal prestige.
Eigenfactor: Similar to the journal impact factor, but does not include citations from the same journal to control for self-citing within the journal.
Source Normalized Impact per Paper (SNIP): Attempts to create a more contextualized citation impact factor by looking comparatively at citations in disciplines and fields.This accounts for variation in disciplinary citation practices and the bias towards 'general' journals versus specialized or clinical journals.
Citations: The number of times a particular work has been cited. Usually reliant on indexing and citation tracking.
Downloads: The number of times a work has been downloaded from a particular database or repository.
Mentions and alternative metrics (altmetrics): Calculated by companies often using proprietary tools, these attempt to estimate the impact that a work has had through a combination of media mentions, shares, saves, and downloads. The altmetrics browser plug-in and the plumx tools embedded in many journals and repositories are two widely used examples.
h-index: The h-index is the number of works authored by a researcher with at least n number of citations. For example, if we have a researcher with 5 publications A, B, C, D, and E with 10, 8, 5, 4, and 3 citations, respectively, the h-index is equal to 4 because the 4th publication has 4 citations and the 5th has only 3. In contrast, if the same publications have 25, 8, 5, 3, and 3 citations, then the index is 3 because the fourth paper has only 3 citations.
g-index: The g-index was created as an alternative to the h-index, specifically to give very highly cited works more weight.
i10-index: Introduced by google scholar, the i10-index indicates the number of academic publications an author has written that have been cited by at least 10 sources