Computational Evolutionary Biology & Bioinformatics

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*j-*index (Todeschini)

$$j=h+\frac{\sum\limits_{k=1}^{12}{w_kX_k\left(h\times \Delta h_k\right)}}{\sum\limits_{k=1}^{12}{w_k} } ,$$### Example

### History

## References

The *j-*index (Todeschini 2011) is a modification of the *h-*index which allows for over-cited publications in the core to increase the overall value of the index. It uses a set of fixed categorical increases over *h:*

k | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
---|---|---|---|---|---|---|---|---|---|---|---|---|

Δh_{k} | 500 | 250 | 100 | 50 | 25 | 10 | 5 | 4 | 3 | 2 | 1.5 | 1.25 |

where \(w_k\), the weight given to each category, is simply \(1/k\), and \(X_k\left(h \times \Delta h_k\right)\) is the count of publications whose citations are at least equal to \(h \times \Delta h_k\).

Essentially this metric adds additional scores to *h* for publications which are cited well more than that necessary for the core, with larger weight given to those much higher than the core value (500 times the core get a weight of 1, 250 times the core get a weight of 0.5, etc.).

Publications are ordered by number of citations, from highest to lowest.

Citations (C)_{i} | 42 | 36 | 14 | 11 | 9 | 9 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 0 | 0 | 0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Rank (i) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |

h = 6 |

k | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
---|---|---|---|---|---|---|---|---|---|---|---|---|

Δh_{k} | 500 | 250 | 100 | 50 | 25 | 10 | 5 | 4 | 3 | 2 | 1.5 | 1.25 |

h×Δh_{k} | 3000 | 1500 | 600 | 300 | 150 | 60 | 30 | 24 | 18 | 12 | 9.0 | 7.5 |

Count C ≥ _{i}h×Δh (_{k}X)_{k} | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 2 | 2 | 3 | 6 | 6 |

Weight (w)_{k} | 1.00 | 0.50 | 0.33 | 0.25 | 0.20 | 0.17 | 0.14 | 0.12 | 0.11 | 0.10 | 0.09 | 0.08 |

w_{k}X_{k} | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.29 | 0.25 | 0.22 | 0.30 | 0.55 | 0.50 |

The sum of *w _{k}*

Year | j |
---|---|

1997 | 1.0000 |

1998 | 2.1803 |

1999 | 3.3257 |

2000 | 5.4112 |

2001 | 6.6778 |

2002 | 7.7935 |

2003 | 9.7703 |

2004 | 12.1640 |

2005 | 14.3768 |

2006 | 16.8052 |

2007 | 18.9074 |

2008 | 21.1863 |

2009 | 25.1645 |

2010 | 26.4376 |

2011 | 28.5540 |

2012 | 29.8242 |

2013 | 32.1643 |

2014 | 35.2275 |

2015 | 37.1586 |

2016 | 38.3459 |

2017 | 38.4342 |

- Todeschini, R. (2011) The
*j-*index: A new bibliometric index and multivariate comparisons between other common indices.*Scientometrics*87:621–639.