Research: Metrics and Impact

h-index

h-index - measures a combination of both productivity and impact.

A scientist has an index h if h of his/her Np papers has at least h citations each, and the other (Np h) papers have no more than h citations each

Hirsch, J. E. (2005). An index to quantify an individual's scientific research output. Proceedings of the National Academy of Sciences, 102(46), 16569-16572. doi: 10.1073/pnas.0507655102

In plain English: If you had:

• 1 paper that has 300 citations
• 5 papers that have 3 citations each
• 8 other papers that have 1 citation each

you would have an h-index of 3 (you have at least 3 papers that have been cited at least 3 times each, but you do not yet have 4 papers that have been cited at least 4 times each).

If any 3 of your papers (except the first one) all rise to 4 citations, your h-index will rise to 4. So, h articles of at least h citations each.

One article cited many times will not raise your index, nor many articles cited a few times each. What you want are more articles all cited more times - overall impact rather than high specific impact or rather than wide but low impact.

Citation rates for specific publications and your h-index are likely to be different in different databases, due to differences in database coverage of different journals and frequency of updates.

Variations of the h-index can also be applied to journals, groups of authors, or selected documents.

Article level metrics are offered by:

Web of Science

Scopus

Google Scholar

 Note: The citation rate for a specific article is likely to be different in different databases due to differences in database coverage and frequency of updates.

Many metric sources will also list journal rankings, at least for the top journals in specific fields or disciplines.

Scimago Journal Rankings (derived from Scopus data)

Google Scholar metrics

MyRI (Measuring your Research Impact) tutorial

1. Introduction to bibliometrics
2. Track your research impact
3. Journal ranking and analysis

Metrics toolkit - for demonstrating and evaluating impact

Altmetrics - 'alternative metrics' - measures social media impact, Mendeley use, and other mentions. The Altmetric 'donut' can be seen on research outputs records in Scopus, research output repositories and in other sources. The colours in the donut relate to the source of the mentions - Twitter, Mendeley, blogs, news sources.   

Install the free Altmetric bookmarklet in Firefox, Chrome or Safari to view Altmetrics on papers in Google Scholar or which have a DOI.

A beginner's guide to altmetrics (video clip from Altmetrics)

Altmetrics (video clip from Altmetrics)

altmetrics: a manifesto: this document discusses the use of altmetrics - new forms of attention that reflect and transmit scholarly impact

• PlumX analytics - measures social media impact, database clicks, and other mentions. Available in CINAHL
• Impactstory - an open-source web-based tool that provides altmetrics to help researchers measure and share the impacts of all their research outputs—from traditional ones such as journal articles, to alternative research outputs such as blog posts, datasets, and software. The metrics provided by ImpactStory can be used by researchers who want to know how many times their work has been downloaded and shared, and also research funders who are interested in the impact of research beyond citations to journal articles.
• Paperbuzz - tracks social media (e.g. Twitter) mentions of scholarly articles using DOIs. Uses ImpactStory data/APIs.
• Scholarometer - measuring impact using Google Scholar and crowdsourcing to select the fields (disciplines) covered by that author (field annotations) in an attempt to measure impact within a field. Still at an early stage, usefulness and reliability will rely on wider ongoing use and participation. Based on a web browser add-on.