← Back to introduction

EM-index

The EM-index (Bihaari and Tripathi 2017) combines elements of the multidimensional h-index, the two-sided h-index, the iteratively weighted h-index, and the e-index. The EM-index begins by creating a vector (E) which is equivalent to the upper/excess half of the two-sided h-index, namely a series of h values calculated from the citation curve of just the core publications, stopping when one reaches only a single remaining publication, no citations remain, or all remaining publications have only a single citation. From this vector, EM can be calculated as:

$$EM=\sqrt{\sum\limits_{i=1}^{n}{E_i}},$$

where Ei and n are the ith element and length of E, respectively.

Example

Publications are ordered by number of citations, from highest to lowest. After each step, Ei is subtracted from the citations of the top Ei publications. All publications beyond the top Ei are ignored at subsequent steps.

Citations (Ci)572616121110432111100000
Rank (i)123456789101112131415161718
E1 = 6
Adjusted Citations (Ci)512010654
Rank (i)123456
E2 = 5
Adjusted Citations (Ci)4615510
Rank (i)12345
E3 = 3
Adjusted Citations (Ci)43122
Rank (i)123
E4 = 2
Adjusted Citations (Ci)4110
Rank (i)12
E5 = 2
Adjusted Citations (Ci)398
Rank (i)12
E6 = 2
Adjusted Citations (Ci)376
Rank (i)12
E7 = 2
Adjusted Citations (Ci)354
Rank (i)12
E8 = 2
Adjusted Citations (Ci)332
Rank (i)12
E9 = 2

The sum of the 9 E values is 26. The EM-index is the square-root of this sum, thus EM = 5.0990.

History

YearEM
19971.0000
19981.7321
19993.7417
20004.1231
20015.0990
20025.6569
20037.0000
20048.4853
200510.1489
200611.7473
200713.5277
200815.4272
200916.7332
201018.2757
201119.4165
201220.7605
201321.9317
201422.8473
201523.8328
201625.0998
201726.4386
201827.7489
201928.7402
202029.4788
202130.0500
202230.7896
202332.6650
202434.8138
202535.2704

References