Other disciplines work in other ways. Pollak's statement was not meant as a
dismissal of mathematics education, but as a pointer to the fact that the
nature of evidence and argument in mathematics education is quite unlike
the nature of evidence and argument in mathematics. Indeed, the kinds of
questions one can ask (and expect to be able to answer) in educational research
are not the kinds of questions that mathematicians might expect. Beyond
that, mathematicians and education researchers tend to have different views
of the purposes and goals of research in mathematics education.