Division lets the subject down
It is true, unfortunately, that the mathematics education world is divided, typified by two professional organisations, the Mathematical Association and the Association of Teachers of Mathematics; and by those who stress "investigation" and tose who stress "didactic teaching" as though one excluded the other.
While there are powerful mathematical educators in higher education who defend their diametrically opposed views with periodic intellectual bare-knuckle fighting, teachers in schools will suffer from the absence of a clear direction for the subject.
Is it not time to establish a (single) "Association for Mathematics Education"?
Brian Wardle School adviser - mathematics Birmingham LEA Balden Road Birmingham