The Feb 1997 issue of Phi Delta Kappan includes an article titled "Constructivist Caution" by Peter Airasian and Mary Walsh. The authors discuss the challenges of implementing constructivist theory in the classroom.
Using the "Kim Mackey Method," I'll tease out a few quotes from the article:
"Do not fall into the trap of believing that constructivist instructional techniques provide the sole means by which students construct meanings. This is not the case. ... What teacher has not taught a didactic, rote-oriented topic or concept only to find that the students constructed a variety of very different meanings from those anticipated by the teacher?
[The authors then point out how the constructivist view on memorization and rote learing is misunderstood by quoting von Glasersfeld who states:] 'There are , indeed, matters that can and perhaps must be learned in a purely mechanical way.' [The authors continue:] "One's task is to find the right balance between the activities of constructing and receiveing knowledge, given that not all aspects of a subject can or should be taught in the same way or be acquired solely through 'hands-on' or student-centered means."