1. LAPS symposium discussion Dylan Wiliam Annual conference of the British Educational Research Association; London, UK: 2007 www.dylanwiliam.net

2. Plus ça change… Teacher judgments are the mechanism of social class disadvantage “Ability” grouping Curriculum polarisation Concentration of (some) resources Teachers’ preferred teaching styles trump organization Scalability of decisions to set by subject Diversity (and secrecy) of setting practices The (pernicious) variance hypothesis Construct-irrelevant (?) variance of setting practices

3. The unreasonable persistence of ability grouping Reasonably clear consensus of the impact of setting on attainment First order effect: small reduction of average attainment Second order effect: increase of variance Third order effect: set x sex interactions (esp. top sets) Persistence of ability grouping practices Is political, not rational –Popular with parents, and politicians –Popular with teachers (at least those in the schools that set)

4. Predictive validity and assessment illiteracy

5. Wiliam & Bartholomew, 2004

6. Suggestions for future work Quantification of impact in terms of rate of learning 1 grade lower is equivalent to learning at half the average speed Disentangling effects of setting from other factors Compositional effects (a necessary feature of setting) Curriculum polarization (a contingent feature of setting) Teacher quality (a contingent feature of setting) –Students taught by the most effective teachers learn at four times the rate of those taught by the least effective Likely that school culture mediates all processes in the model But, setting remains a mechanism that allows middle-class parents to secure the most important advantage in the system: teacher quality