Mitigating ageing bias in article level metrics using citation network analysis

Abstract Article level scientometric indicators (ALMs) are usually of cumulative nature making articles of different age hard to compare. Here, we introduce a new ALM, the Time Debiased Significance Score (TDSS), which measures the significance of a publication based on the structure of the whole citation network and eliminates the global ageing bias in the network: older publications should not be a priori privileged or disadvantaged compared to newer ones. The TDSS is based on a modified variant of the PageRank measure, incorporating a mathematically consistent temporal detrending and ensuring a few key features: (i) the TDSS should not show any global trend as a function of the topological index (causal order in the citation network); (ii) the TDSS value of a publication should decrease as time passes (and the citation network grows) if no more citations are associated with it. The above definition is beneficial in multiple ways, including e.g. low computational complexity and weak domain dependence. Further, estimation of reliability of the TDSS and its extension to groups of items like overall score of a research group are also possible.