Excellent reference. Papert created his own theory called constructionism based on the tenants of learning by doing and accumulated knowledge acquisition (genetic epistemology). He emphasized making learning tools meaningful and relevant to children, so that they could use their prior experiences to help model new concepts. With LOGO, children used imperatives to command a turtle around on screen. When things went wrong, children could "act like a turtle" to debug, often by physically acting out the commands themselves. He called it body syntonic learning, as opposed to the more traditional disassociated learning we typically see. Shameless plug: I recently wrote more about this in a review of the book "Mindstorms" that this was an excerpt from: http://bsumm.net/2012/07/01/mindstorms.html