I think there were two sets of results.
PPl with BBB and below, trhere was a clear difference.
PPL with AAA and above, there was no difference.
I can believe that. If Tim Nice-but-dim goes to an expensive school, they might wang him up from CCC to BBB, but nobody is going to get him close to AAA.
Ppl with AAA and above are clever, wherever they went to school. So they're all clever. So there's no difference.
What I hoped this research would tell us, is whether there's a population of BBB state educated kids who are performing as well as AAA independently educated kids. The research seems to say no, there isn't. Which is probably the most important thing we all wanted to know.