The purpose of this research is to illustrate the use of the gamma distribution to model the ages of references in published research, and to demonstrate that the two gamma distribution parameters characterise a field of research in a manner that is complementary to and more nuanced than the Price Index or mean age of references.

Minimum Distance Estimation is shown to produce robust estimates of the gamma distribution parameters because of the insensitivity of the Kolmogorov–Smirnov test in the tails of the distribution.

Using a sample of 816 articles from 26 different journals across six subject areas, it is shown that the gamma distribution is at least as good as a lognormal distribution to model the ages of references in research articles.

The two gamma distribution parameters indicate the rate of publication of new knowledge within the respective discipline and the citing behaviour in terms of the recency of references. Interpretation of these gamma distribution parameters enables a more nuanced and granular interpretation of the distinctiveness of disciplines, sub-disciplines, formats of publication and the distribution of references within articles than possible using the Price Index, half-life or mean age of references.

这项研究的目的是说明使用伽玛分布来模拟已发表研究中参考文献的年龄，并证明这两个伽玛分布参数以一种补充和细化的方式表征了一个研究领域。价格指数或平均参考年龄。

由于Kolmogorov-Smirnov检验在分布的尾部不敏感，因此显示了最小距离估计可以对γ分布参数产生可靠的估计。

使用来自六个主题领域的26种不同期刊的816篇文章的样本，可以证明，伽马分布至少与对数正态分布一样好，可以为研究文章中的参考文献年龄建模。

这两个伽玛分布参数指示相应学科内新知识的发布速度以及根据参考文献的引用行为。解释这些伽玛分布参数可以比使用价格指数，参考文献的半衰期或平均年龄更细致，更精细地解释学科，子学科，出版物的格式以及参考文献在文章中的分布。