Your proposed test for bias would be reasonable for a traditional school, but although the linked post focuses on how Hacker School has fared in regard to gende

Your proposed test for bias would be reasonable for a traditional school, but although the linked post focuses on how Hacker School has fared in regard to gender diversity, Hacker School stands out more for its diversity of programming skills and skill levels, from near-beginners to CS PhDs, as part of the goal of maximizing how much the students can learn from each other. You're overlooking this important part: "We accept every person who applies who we believe we’re a good fit for and who would benefit from and contribute to Hacker School." This is of course ultimately a subjective standard, and any serious attempt to evaluate their success in meeting it is bound to be highly subjective as well. You might think that focusing less on raw programming ability would be an excuse for bias, but from what I saw in the batch I attended last year they achieved a very healthy balance along those dimensions for both men and women. It's to the facilitators' credit that if you removed either all the men or all the women from my batch, it would still be the most well-rounded group of programmers I've ever worked with, which again is admittedly subjective, but even as a white male as prone to statistical nitpicking as you are, I can't think of a better way to judge that they really do admit men and women, as individuals, in a way that aligns with their more holistic objectives for HS as a community of individuals.