According to a study done by Helmut Fend (who had always been a fierce proponent of comprehensive schools) revealed that comprehensive schools do not help working class students. He compared alumni of the <answer>tripartite system</answer> to alumni of comprehensive schools. While working class alumni of comprehensive schools were awarded better school diplomas at age 35, they held similar occupational positions as working class alumni of the <answer>tripartite system</answer> and were as unlikely to graduate from college.
To which system did Fend compare comprehensive school alumni?
tripartite system