This TC will help OMJ to compare the a achievement of students from the Colegios Peruanos schools network and the quality of teachers, with a control group to determine potential differences and understand the reasons behind them. The final purpose is to compare student achievement and teacher quality with those of the public system and similarly priced private models. Students will be assessed in terms of (i) Spanish skills, (ii) Science and math competencies, (iii) English skills, (iv) repetition rates, (v) involvement in extra-academic activities. Teaching quality will be measured in terms of: (i) teacher selection criteria , (ii) training and development, (iii) instruction quality, (iv) incentives