Petr Maj

Emery D. Berger, Petr Maj, Olga Vitek et al.

Ray, Devanbu and Filkov issued a rebuttal of our TOPLAS paper "On the Impact of Programming Languages on Code Quality: A Reproduction Study". Our paper reproduced "A Large-Scale Study of Programming Languages and Code Quality in GitHub", which appeared at FSE 2014 and was subsequently republished as a CACM research highlight in 2017. This article is a rebuttal to that rebuttal.

Emery D. Berger, Celeste Hollenbeck, Petr Maj et al.

This paper is a reproduction of work by Ray et al. which claimed to have uncovered a statistically significant association between eleven programming languages and software defects in projects hosted on GitHub. First we conduct an experimental repetition, repetition is only partially successful, but it does validate one of the key claims of the original work about the association of ten programming languages with defects. Next, we conduct a complete, independent reanalysis of the data and statistical modeling steps of the original study. We uncover a number of flaws that undermine the conclusions of the original study as only four languages are found to have a statistically significant association with defects, and even for those the effect size is exceedingly small. We conclude with some additional sources of bias that should be investigated in follow up work and a few best practice recommendations for similar efforts.