# Michael S. Rosenberg’s Laboratory

Computational Evolutionary Biology & Bioinformatics

E-mail: msr@asu.edu
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## h2-tail index

The h-index describes an h×h square under the citation curve containing h2 citations. Bornmann et al. (2010) suggest dividing the citation curve into three sections based on this square and describing each section as the percent of all citations found within the section.

The h2-tail index is the percent of citations found within the tail of the citation curve, i.e., the citations of publications outside the h-core. It is calculated as:$$h_\text{tail}^2=\frac{C^P - C^H}{C^P}\times 100=\frac{\sum\limits_{i=h+1}^{P}{C_i}}{C^P}\times 100$$

### History

Year$$h_\text{tail}^2$$
199750.0000
199830.7692
199913.8889
200013.4328
20019.0226
200214.1667
200314.7139
200413.3333
200511.4793
200610.9694
200710.0729
20088.7302
20095.9154
20106.8532
20116.9008
20127.0774
20136.2778
20144.3885
20153.7459
20163.1731
20173.4244

## References

• Bornmann, L., R. Mutz, and H.-D. Daniel (2010) The h index research output measurement: Two approaches to enhance its accuracy. Journal of Informetrics 4:407–414.