A careful model-based analysis of AP CS 2013 exam data: CS commenters need to learn statistics
There has been a lot of media attention to Barb’s analysis of AP CS 2013 exam data, but not all of it has been well-informed. We both really enjoyed reading the Gas Station Without Pumps analysis, quoted and linked below. Not only is it a careful, model-based analysis, but it’s a nice explanation too. I learned more about how to measure under-representation — recommended reading.
There are states that do have significant under-representation of women: for example, Utah had 103 test takers, only 4 of whom were women. With an expected number of about 51.5, this is p<1.4E-16. Even with 51× multiple hypothesis correction, this under-representation is hugely significant. Looking nationwide, total counts were 5485 female test takers out of 29555 total test takers. That’s p< 1.4E-1677. The highest percentage of female test takers was in Tennessee, with 73 out of 251, which is p< 2.6E-7, again highly significant.
Tennessee also had a high proportion of black test takers with 25 out of 251. With an expected number of 42.12, this is p<0.003 (still significantly under-represented). To see if black students were under-represented nationwide, one would have to add up the expected numbers for each state and see how the actual number compared with the expected number.