Teacher specialization is the idea that elementary school teachers no longer teach all topics, but instead focus on just a few. As all teachers of a certain grade will specialize in a limited number of topics, the overall number of teachers per students remains the same, but each teacher has much more time to invest in his/her topic. The idea is that this specialization has a positive effect on the teachers' teaching quality and on the pupils' performance.
This idea was tested in recent large-scale experiment by Fryer (2016). This two-year long study took place in grade 3 through 5 of 50 schools in Texas (USA). Half of the schools continued teaching as usual, while in the other half the teachers specialized. What didn't change was that the teachers kept teaching (only) their own grade, and the class formations were not changed. This study focused specifically on math and reading ability.
Despite the positive expectations, the pupils of the specialized teachers performed worse than the pupils in the control condition. This effect was specifically visible in the first year of the study. In the second year the detrimental effect is reduced. Furthermore, when we look at both years combined there is no difference between the specialized and non-specialized schools at the end of the two years.
While it is a interesting topic and study, it is challenging to generalize from this study. It is likely that the negative effect visible in the first year is mainly because the teachers and pupils had to get used to this new form of education. This would explain why the negative effect disappears over time. However, this gives no guarantee that there will be positive effect of teacher specialization after the first two years. Overall, this study cautions us that teacher specialization can - at least in the short term - have a negative effect on pupils' performance.
Fryer Jr, R. G. (2016). The'Pupil'Factory: Specialization and the Production of Human Capital in Schools. National Bureau of Economic Research.