Types of bibliometrics

Different bibliometrics work in different ways. Here are some of the most common:

Non-normalised bibliometrics

Citation count (Non-proprietary)  

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.

Citation counts will be found from the publisher page or indexing services like Google Scholar, Dimensions, Scopus and Web of Science.  Citation counts vary across citation providers.

Health Warning: simple (raw) citation counts are not normalised by time, publication type or discipline – all of which will impact the citation count of a publication.  To take account for these variances citation providers provide proprietary normalised measures.

H-index (Non-proprietary)

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.

Health Warning: Person based metrics are typically not normalised by discipline and favours established researchers with a longer publication record, it disfavours Early Career Researchers and researchers who have had career breaks.

Journal Impact Factor (Supplied by Clarivate)

The Journal Impact Factor (JIF) is calculated by taking the number of citations for that journal in the last two years and dividing it by the number of citable items in said journal.  So if a journal has an Impact Factor of 3.2, a publication from that journal will typically have received 3.2 citations.

Health Warning: Shouldn’t be used as a metric for the value of an individual publication – it’s a metric for the journal not the article.  Considered the worst metric by DORA, it’s an easily gameable metric for a journal, and not relevant for an individual paper that appears in that journal. It should be used with maximum caution, if at all. 

Normalised bibliometrics

Field Weighted Citation Impact (Supplied by Elsevier)

The Field Weighted Citation Impact (FWCI) is defined by whether a publication (or set of publications) is cited more than the average publication in the same time period, same document type and in the same discipline, e.g., a value of 2 tells us the publication has been cited twice as much as an average document of the same time period, document type and discipline.

Publications in Top percentiles (Supplied by Elsevier)

Publications in top percentiles measures whether a publication appears in the in the top 1%, 5%, 10% or 25% of publications published in the same time period and in the same discipline.  If a publication is in the 99th percentile it is in the top 1%.

Field Citation Ratio (Supplied by Digital Science)

Field Citation Ratio (FCR) is calculated by dividing the number of citations a paper has received by the average number received by documents published in the same year and in the same Fields of Research (FoR) category.

Journal Citation Indicator (Supplied by Clarivate)

Journal Citation Indicator (JCI) normalises citations to take into account citation differences related to discipline, document type and age of publication.  So, the average will be 1, any score over 1 will be above the average.