As I was reading Yasmin's Kafai's chapter on Constructionism from the Cambridge Handbook of the Learning Sciences, I couldn't help but think about James Greeno's chapter from the same text. They present two different, but compatible, theories of learning. (To be clear, I mean "theory" scientifically, as a way to explain data collected by experimentation or observation, not "theory" colloquially, as an idea or thought one has about something.) It felt to me that Greeno was writing about learning as participation in activity and Kafai was writing about learning as acquiring knowledge through construction. I remembered another piece I read a while ago by Anna Sfard where discussed learning through the participation and acquisition metaphors and cautioned against privileging one over the other. I don't think that Greeno or Kafai (at least in these pieces) was trying to say that their individual learning theory was superior to any other one. However, it is tempting to try to explain all learning through one lens... even though I think it's pointless.
I know I shouldn't pick on this, but Kafai's chapter seemed less like a survey of constructionism as it did a homage to the work of Seymour Papert. That said, it was an interesting read. I don't think I ever really considered the differences between constructivism and constructionism. It's easy to say that constructivism is a theory of knowledge while constructionism is a theory of learning, but that doesn't really explain the difference. At the core, constructivism is descriptive (what are the stages of knowledge development) where constructionism aims to be prescriptive (what teachers can do to induce learning). You can't teach a little kid object permanence. Either he has or he doesn't. But you can give a little kid Logo and help them figure out how to draw a square.
Chapter 6 from How People Learn was also an insightful read. At the beginning, I was fearful that it was going to advocate for a Learner-Centered environment over a Knowledge-Centered environment. Then the authors introduce Assessment-Centered and Community-Centered environments and I got all confused. I found it satisfactory to learn that the authors were saying that all four of these centers should be present in any kind of learning environment. I've always found that a good theory should helpfully explain what I already know. These four things seem so obvious now that they've been named. A good teacher will try to figure out what students bring to the classroom and leverage that information into the design of the environment (learner-centered). She will also make sure that norms and ways of knowing and core concepts of the discipline are a major component of the course work (knowledge-centered). Of course, the teacher needs to figure out what students have learned and must give students feedback about what they still need to learn (assessment-centered). And the classroom is a community located within and alongside other communities. The teacher has to take that into account when designing activities (community-centered). I think I try to do these things but I have to be more intentional about them.
Personal aside: Since I've read a few different pieces about computer programming (Kafai's Constructionism chapter and Resnick et al's short piece on Scratch) I've become even more convinced that including some programming in my math classes could enhance student learning. I just have to figure out how to incorporate it. I was the kid who learned to program in Basic in elementary school and I tinkered with Logo in an after school program. I taught programming early in my career and I really wish I had kept up with it. My skills are rusty, but I think I should pick it up again.