Comments on "Detecting Outliers in Gamma Distribution" by M. Jabbari Nooghabi et al. (2010)

Abstract

This note shows that the results presented by Jabbari Nooghabi et al. (2010) do not hold in all expected cases. With this, the technique proposed by Kumar and Lalhita (2012) for detecting upper outliers in Gamma samples is also not valid. Specifically, this note shows that the probability density functions (pdf) under the null hypothesis of the test statistics therein proposed are not always valid.