Hwang and Kisida looked to develop a causal model using quasi-experimental methods to assess the effectiveness of subject-area specialization for teachers in elementary school. The authors compared the effectiveness of a teacher in a year when the teacher had a specialization role to a year when the teacher did not have a specialization role. This limited the study to those teachers who were both specialists (teach 1 or 2 subjects out of 4 major subjects) and generalists (teach 3 or 4 subjects) within the timeframe of the study (12% of all math teachers and 36.7% of all reading teachers fit this description). However, given the relatively large sample from the Indiana Department of Education, containing 15,895 math teachers and 17,102 reading teachers, the authors were able to use this model to estimate effects related to teacher specialization. The findings were shown below.
- A teacher’s effectiveness was lower when teaching math as a specialist than when teaching as a generalist (ES = -0.04). The situation was worse during the teacher’s first year of specialization (ES = -0.05).
- The decrease in teacher effectiveness was particularly noticeable when teaching students from historically underserved populations. In math, Black students and Hispanic students both experienced larger negative effects in comparison to White students.
- Students in the lowest quartile of achievement also experienced a larger negative effect than students in the highest quartile of achievement.
The authors suggested that student-teacher relationships are more difficult to maintain in a specialist format, which may help to explain the differences in student outcomes. The authors then concluded that teacher specialization does not benefit students when compared to generalization, and appears to be particularly detrimental for certain groups of students.
Source: Hwang, N., & Kisida, B. (2022). Spread Too Thin: The Effect of Specialization on Teaching Effectiveness. Educational Evaluation and Policy Analysis, 016237372210843. https://doi.org/10.3102/01623737221084312