h(2)-index
The h(2)-index (Kosmulski 2006) is similar to the h-index, but rather than define the core based on h publications having h citations, this index requires the h publications to each have h2 citations:
$$h\left(2\right)=\underset{i}{\max}\left(i^2 \leq C_i\right).$$This leads to h(2) having a stricter definition of the core publications than many other metrics.
Example
Publications are ordered by number of citations, from highest to lowest.
| Citations (Ci) | 47 | 26 | 19 | 15 | 11 | 10 | 4 | 3 | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rank-squared (i2) | 1 | 4 | 9 | 16 | 25 | 36 | 49 | 64 | 81 | 100 | 121 | 144 | 169 | 196 | 225 | 256 | 289 | 324 |
| Rank (i) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| h(2) = 3 |
The largest rank where i2 ≤ Ci is 3.
History
| Year | h(2) |
|---|---|
| 1997 | 1 |
| 1998 | 1 |
| 1999 | 2 |
| 2000 | 3 |
| 2001 | 3 |
| 2002 | 4 |
| 2003 | 5 |
| 2004 | 6 |
| 2005 | 7 |
| 2006 | 8 |
| 2007 | 8 |
| 2008 | 8 |
| 2009 | 9 |
| 2010 | 10 |
| 2011 | 11 |
| 2012 | 11 |
| 2013 | 11 |
| 2014 | 12 |
| 2015 | 12 |
| 2016 | 13 |
| 2017 | 13 |
| 2018 | 14 |
| 2019 | 14 |
| 2020 | 14 |
| 2021 | 14 |
| 2022 | 15 |
| 2023 | 15 |
| 2024 | 15 |
References
- Kosmulski, M. (2006) A new Hirsch-type index saves time and works equally well as the original h-index. ISSI Newsletter 2(3):4–6.