Conclusion

This study found no benefit, on average, to student achievement from placing an AC teacher in the classroom when the alternative was a TC teacher, but there was no evidence of harm, either. In addition, the experimental and nonexperimental findings together indicate that although individual teachers appear to have an effect on students' achievement, we could not identify what it is about a teacher that affects student achievement. Variation in student achievement was not strongly linked to the teachers' chosen preparation route or to other measured teacher characteristics.