An indicator of journal impact that is based on calculating a journal's percentage of highly cited publications

TL;DR

This paper introduces a field-normalized, robust journal impact indicator based on the percentage of highly cited publications, addressing limitations of impact factor and h-index for cross-category comparisons.

Contribution

It empirically compares this new indicator with impact factor and h-index across various time windows and citation thresholds, demonstrating its advantages.

Findings

The new indicator is field normalized and comparable across categories.

It is robust to highly cited articles and independent of journal size.

The indicator provides a more equitable measure of journal impact.

Abstract

The two most used citation impact indicators in the assessment of scientific journals are, nowadays, the impact factor and the h-index. However, both indicators are not field normalized (vary heavily depending on the scientific category) which makes them incomparable between categories. Furthermore, the impact factor is not robust to the presence of articles with a large number of citations, while the h-index depends on the journal size. These limitations are very important when comparing journals of different sizes and categories. An alternative citation impact indicator is the percentage of highly cited articles in a journal. This measure is field normalized (comparable between scientific categories), independent of the journal size and also robust to the presence of articles with a high number of citations. This paper empirically compares this indicator with the impact factor and the h-index, considering different time windows and citation percentiles (levels of citation for considering an article as highly cited compared to others in the same year and category).