The Productivity of CS Teachers

On the way out to the NSF Broadening Participation in Computing (BPC) community meeting in Los Angeles,  Barb was working on the NCWIT K-12 Alliance Strategic Plan.  (She’s co-chair of the Alliance.)  She was reviewing data from the Advanced Placement exams, and came across something interesting.

Physics is a big dog among the science AP exams.  In 2008, 55,227 students took the Physics AP exam.  (Biology had 141,321 test-takers in 2007, as another point of comparison.) In contrast, only 15,014 students took the CS Level A AP exam.  CS is only 27% of the Physics total.

She pointed out to me that there are many more Physics teachers than CS teachers.  In 2007, there were 4316 Physics AP teachers, while there were only 2,068 CS AP teachers.

I started digging into her data a bit more and found that in 1998, there were 2510 Physics teachers and 1208 CS teachers.  In that year, there were 23,315 students taking Physics AP exam, 6144 tacking CS Level A AP exam.

So, here’s what I’m getting at.  In 1998, each Physics AP teacher got about 19 students to take the exam.  In 2008  (I only have 2007 test-takers data, so there’s a year smudge here), the productivity dropped to 13 test-takers per teacher.  In 1998, each CS teacher produced 5 test-takers, while in 2008, that was 7 test-takers per teacher.

CS teachers are becoming more productive (in terms of test-takers) while Physics is dropping slightly.  That productivity is important.  Test-takers are more likely to pursue more courses in that subject in college than non-test-takers.  It’s a good thing that the productivity is rising.  On the other hand, there is lots of room for improvement.  If our current AP CS teachers produced test-takers at the same level as AP Physics teachers, we would have 26,884 test-takers — way past the 20,000 students needed for the College Board to break-even on offering the exam.

How do we increase  teacher productivity?  Is it more students per class?  Or is it that we have to get more students to take the test?  It’s a really interesting question — what does it mean to improve productivity in an educational system?