An article in the March 2 issue of Science (Vol. 335, p. 1118-1121) demonstrates that while teacher effectiveness rises during the first four years of a teacher’s career in all subjects, the gains are most dramatic in chemistry and physics.
A trio of researchers from the University of North Carolina at Chapel Hill and Georgia State University studied results from North Carolina’s exemplary program of end-of-course exams (which was recently cut due to budget considerations). They compared “Teachers’ Average Value-Added Test Score Gains” in units of “Standard Deviation Units” (SDU), the one-sigma spread in student test scores in a particular EOC exam.
During teachers’ first four years in the classroom, biology teachers’ gains are about 0.10 SDU, while those in Geometry, Algebra 2 and Physical Science are near 0.15 SDU. In contrast, the corresponding gain for chemistry teachers is near 0.27 SDU, and the physics gain is an astounding 0.37 SDU.
The authors conclude:
Different high-school subjects show different impacts of teacher turnover. For courses with steeper effectiveness growth curves – physics, chemistry, and geometry – the loss of these experienced teachers has the greatest consequences for student performance. For courses with less steep growth curves – algebra 1, algebra 2, biology, and physical science – the loss of more experienced teachers has less severe consequences. But both cases call for recruiting more able, motivated, and committed teachers. Could these teachers be better screened by evaluating their academic performance, persistence, ability to engage audiences, and projected commitment to teaching, specifically teaching STEM courses to high-school students? Would incentives, such as higher salaries, assignment to fewer courses per year, or paid opportunities for research with university faculty during summers or semester leaves, help retain more of the experienced teachers?
These results make the present exodus of experienced physics teachers from North Florida high schools even more disturbing.
Thanks to Alan Dorsey for bringing this article to my attention.