It seems that we need some concrete research on the value of manipulative in math education. * Are they only beneficial if the manipulatives are used in a constructivist manner? * Are they more or less beneficial for various age groups, concepts? * Is there truly a teaching technique, employing manipulatives, that could be destructive to learning in math? * In otherwords could manipulatives be "educational poison" in the wrong hands?
It seems that the time is ripe to seriously study this issue and perhaps put the controversy to bed once and for all. I'm game if anyone else is interested.