This morning Mark Guzdial tweeted on his latest post:
Results from Longitudinal Study of Female Persistence in CS: AP CS matters, After-school programs and Internships do not https://t.co/GOzp3045Hp— Mark Guzdial (@guzdial) October 14, 2019
I'm glad Mark wrote about this as it's something that's important to both research and publicize but it's really not a surprise.
I'm going to start by dismissing the statement that "… participation in the Aspirations awards program were teh best predictors of persistence three years after the high school survey in both CS and other technology-related majors." To me, that's a water is wet statement - girls who apply for an award where they talk about their aspiriations in computing are more likely to do more computing.
The other stuff merits more of a look. Classes and APCS-A in particular vs after school programs. Since APCS-A is as far as I know always an elective there's probably some selection bias here. If a girl elects to take a college level CS class, perhaps there's already some interest in pursuing CS in college. Further, and I really hate to say this, given the male dominated aspects frequently present in our CS classes, a girl who was interested in CS and survives APCS-A might be more likely to continue on and succeed having weathered the storm.
Now let's look at the out of school programs. There are a number of issues here. Many don't really cover CS or legit programming, many allow one group member to basically carry the team, and many are really entrepreneurship programs using the CS marketing hype. They don't really prepare students for what's to come in CS. When a student then takes a CS class in college they're ill prepared and drop the subject. I've seen it happen. Unfortunately, many of those after school programs are masters of marketing and fundraising. Some get big money from the Googles of the world but they're never held accountable for preparing kids to fail. Rather, they're lauded and praised as saviors of education.
Going further, after school programs are usually taught by volunteers, not teachers. They don't necessarily understand the nuances of teaching and they don't necessarily prepare you for your next CS experience. You then end up in a college course of 300, are ill prepared to succeed, fall through the cracks and drop out. Take APCS-A in HS and you're going to be in a class of 30 and in a much more supportive, forgiving environment. A much better place to prepare you for what's to come.
All in all the idea that girls are more likely to follow a CS path with a solid high school experience than with an outside club or activity is hardly a surprise. What is more of a surprise to me is the fact that it's taken so long to start getting the word out.