hm-index
While the normalized hi-index accounts for the number of authors of a publication by normalizing the citation count for that publication, hm (Schreiber 2008), also known as the fractional paper h and hF-index (Egghe 2008), accounts for author number by normalizing the ranks. For this index, one counts the number of citations and ranks the publications as for the h-index, but rather than counting the rank of the ith publication as i, it is instead calculated as the cumulative sum of 1/Ai. In formal terms, when calculating the h-index the rank of the ith publication is
$$r_i=\sum\limits_{j=1}^{i}{1}=i.$$For hm we instead calculate the effective rank as
$$r_{\text{eff}}\left(i\right)=\sum\limits_{j=1}^{i}{\frac{1}{A_i}}.$$hm is determined as the largest value of reff(i) for which reff(i) ≤ Ci or
$$h_m=\underset{r_{\text{eff}}\left(i\right)}{\max}\left(r_{\text{eff}}\left(i\right) \leq C_i\right).$$Example
Publications are ordered by number of citations, from highest to lowest.
Citations (Ci) | 57 | 26 | 16 | 12 | 11 | 10 | 4 | 3 | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Authors (Ai) | 3 | 3 | 2 | 3 | 1 | 4 | 4 | 4 | 1 | 4 | 2 | 1 | 1 | 4 | 2 | 1 | 1 | 1 |
Author Effort (Ei = 1/Ai) | 0.33 | 0.33 | 0.50 | 0.33 | 1.00 | 0.25 | 0.25 | 0.25 | 1.00 | 0.25 | 0.50 | 1.00 | 1.00 | 0.25 | 0.50 | 1.00 | 1.00 | 1.00 |
Rank (i) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
Adjusted Rank (reff(i) = ΣEi) | 0.33 | 0.67 | 1.17 | 1.50 | 2.50 | 2.75 | 3.00 | 3.25 | 4.25 | 4.50 | 5.00 | 6.00 | 7.00 | 7.25 | 7.75 | 8.75 | 9.75 | 10.75 |
hm = 3.00 |
The largest adjusted rank where reff(i) ≤ Ci is 3.0000.
History
Year | hm |
---|---|
1997 | 0.5833 |
1998 | 1.4167 |
1999 | 1.6667 |
2000 | 3.0000 |
2001 | 3.0000 |
2002 | 4.7778 |
2003 | 5.9206 |
2004 | 8.1706 |
2005 | 9.7615 |
2006 | 10.4282 |
2007 | 13.6782 |
2008 | 13.9282 |
2009 | 15.9282 |
2010 | 16.7691 |
2011 | 17.7155 |
2012 | 18.8267 |
2013 | 18.8267 |
2014 | 18.8267 |
2015 | 19.0767 |
2016 | 19.2195 |
2017 | 19.2195 |
2018 | 20.7886 |
2019 | 21.7886 |
2020 | 22.8052 |
2021 | 22.9302 |
2022 | 22.9302 |
2023 | 22.9302 |
2024 | 24.0104 |
References
- Egghe, L. (2008) Mathematical theory of the h- and g-index in case of fractional counting of authorship. Journal of the American Society for Information Science and Technology 59(10):1608–1616.
- Schreiber, M. (2008) To share the fame in a fair way, hm modifies h for multi-authored manuscripts. New Journal of Physics 10:040201.