This is a study of the educational achievements of graduates of an experimental school in comparison to those of a regular school. The experimental school aims to enhance school effectiveness in coping with individual differences and to mediate between private and public knowledge. A quasi-experimental method was used. The results show an advantage for all graduates of the experimental school (i.e. the excellent, average and slow) in most of the variables measured: test results, skills, self-efficacy and motivation. We suggest that the overall systemic framework of the experimental school contributed to its increased effectiveness.