Indices

h-index

The h-index is defined by the number of publications with at least that number of citations each. It is an index which attempts to balance the productivity (# of papers) and impact (# number of citations) of scientific work. It has become the most widely used citation analysis tool to compare the research output of Academics worldwide. The h-index was first proposed by Physicist Professor Hirsch “An index to quantify an individual’s scientific research output”

Notwithstanding any inherent limitations of reducing the output of a particular researcher to a single indicator, the h-index is able to provide insightful information about researchers amongst their peers. It does however have some limitations even when used as a tool for comparison amongst a relatively homogenised group of researchers, being insensitive to:

  • length of career
  • # of researchers per publication
  • Position of researcher on publication list

m-index

The m-index is the normalisation of a h-index taking into account the number of years since the authors first publication. That is if ‘n’ is the number of years since the first publication, then m = h/n.

i10-index

The i10 index is used by Google Scholar. It is defined as simply the number of papers an author has that have 10 or more citations each.

Median normalised m-index

The calculation of the median normalised m-index used for ranking Institutions based on the citation and publication information obtained from Google Scholar is calculated as:

Median normalised m-index = median(\frac{m-index_i}{m-index_{sm}})
where

m-index_i  =m-index of individual staff member

m-index_{sm}  = median m-index for all staff at the seniority level of m-index_i

A median normalised m-index above 1 indicates the University department has more staff with m-index values above the corresponding median m-index in comparison to their seniority level. The converse is true for values less than 1.