Further investigations into the first-citation process : the case of population genetics

Abstract

In this article the first-citation process is investigated. Former studies led to two double exponential models for this process. The first model resulted in a concave function, the other one in a function with an inflection point (an S-shaped function). Real data using a year as time unit could best be described by the first model, data using two weeks as a unit could best be described by the second one. In this note we show that for a group of nine related data sets in the field of population genetics, using one year as a unit, the first observation is confirmed: the concave model can adequately describe such data.