Suppose you teach addition, multiplication, and division. One teaching approach spends all time teaching addition. The other teaching approach teaches all three

Suppose you teach addition, multiplication, and division. One teaching approach spends all time teaching addition. The other teaching approach teaches all three topics. An exam is given only over addition, and the first teaching approach leads to better scores. It would be unwise to conclude from this that the second teaching approach should be discarded. Just for clarity purposes, this is exactly the point of my original comment. The active learning approach may very well be doing a better job preparing students for the test. That's why we should be cautious about concluding students are too dumb to know they're learning more that way. There's more than one interpretation of the data.