Now you will have noticed that all I have done here is to recite what happened when I
followed a few threads in the literature of research into mathematics education. I found one
paper that referred to three papers and in all of them I found no enlightenment. Then I
looked into one book that had been suggested as a good model, and found a fatally flawed
experimental design. Maybe there are other research efforts out there that do better. Well,
maybe there are. I don’t claim to have done any research into research. I just pulled on
these threads to see where they went, and they unraveled. I am not sanguine about the
totality of enlightenment that lies out there.