Now, how differently should we think about this system with the research support that Peter has given us? I’d argue, not much differently. It’s not that there’s no evidence, and it’s not that he’s playing loose with the facts. It’s just that the evidence is weak. It doesn’t support big generalizations. You wouldn’t want to bet the bank on it.

Here’s why:

He doesn’t measure learning at all, only engagement.

He only measures engagement for vertical whiteboards and maybe homework, not for any other component of his system.

He counts teacher uptake as evidence of student engagement.

The measurements he reports are all for older kids.

We don’t know how he selected the groups he measured.

We have no idea where the percentages he reports are coming from in his book.

In fact none of what he did to arrive at his results is particularly transparent, which is probably why his four papers are published in books and conference proceedings, but not journals.