There&#x27;s a large drop for both men and women between project outsiders who do not identify a gender on GitHub and those that do. So that&#x27;s one very clear effect. If you want to have your contributions accepted on GitHub, male or female, and you are an outsider, do not identify yourself.<p>However, it was only possible to identify the gender of about a third of people overall from publicly available information.<p>So for the conclusions of the study to be valid, one must eliminate the possibility that there is a gender imbalance in those whose gender is able to be identified by publicly available information (which would not represent discrimination, since that information is self-reported). Until one can eliminate this, one may not be measuring discrimination, but effectively just a correlation between availability of public information on programmers and their skill level.<p>Moreover, it looks like the gender information was entirely constructed from Google+. Yet there is no information on what percentage of users&#x27; of each gender actually had Google+ pages. This is extremely relevant to the conclusions as there could also be correlations with the usage of Google+ by programmers of a certain skill and gender.