Does school-based initial teacher training affect secondary school performance?

This article investigates the effects of trainee teachers on secondary school student outcomes. The additional resources which schools receive from being involved in teacher training offer them an opportunity to raise standards, but this has to be set against the possible losses due to school students being taught by inexperienced beginning teachers and the diversion of mentors' efforts away from the classroom. Inspection evidence is used to assess whether trainee teachers affect school students' test and examination results. The findings of this research are that the number of trainees has no significant effect on school results at A-level or General Certificate of Secondary Education (GCSE), or on the overall value added between Key Stage 3 and GCSE level. However, at Key Stage 3 level at age 14, while there appears to be a very small depressing effect on achievement in schools with low numbers of trainees, there is a significant positive effect on achievement in schools with larger numbers of trainees.