What is a good high school? Questions of measurement.

Summary Measuring a school's ability to help its students progress is a complicated exercise. For example, baccalaureate success rates tell us little about a school's ability to support all of its students, to enable them to build a career plan and to give them the means to achieve it. Above all, a school's results are very largely linked to the initial level of its students: high success rates may reflect the degree of selectivity in recruitment more than the quality of student follow-up. Finally, indicators of a school's average success rate provide only imperfect information about the success of all its students. A study conducted on the basis of the results of the 2010 baccalaureate shows that, taking into account the social and academic composition of schools, some lycées tend to increase the differences in academic level between the students they enrol, while others manage to reduce the differences in success without sacrificing the average level.