Lately I have been receiving numerous requests for contributions to commemorative publications, farewell speeches, and anniversary lectures. I cannot respond to all of these requests, especially since not all of them are as inspiring as the one today: the 25th (in words: the twenty-fifth!) wave...

The question of the effects of ability tracking remains unresolved even after decades of research. This is also due to the fact that specific regulations for the stringency of implementing differentiation according to ability and achievement have not been taken into account. The issue is the...

It is still taken for granted that (early) ability tracking increases the impact of social origin on achievement in (lower) secondary education, but without gains in the overall level. This contribution addresses the question of whether this common conviction is really correct. The various...

Lately I have been receiving numerous requests for contributions to commemorative publications, farewell speeches, and anniversary lectures. I cannot respond to all of these requests, especially since not all of them are as inspiring as the one today: the 25th (in words: the twenty-fifth!) wave...