The main failures of Piaget's work is that it assumes a smooth progression in reasoning facilities with age and secondly, that its notion of formal operations rests too much on deductive logic. But humans do not really reason logically: affirming the consequent and denying the antecedent are fallacies often encountered. However, as the 19th century logician Peirce once stated, Not the smallest advance can be made in knowledge beyond the stage of vacant staring, without making an abduction at every step.

A famous counter-example is an abstract selection task which adults fail with high probability. Yet, when a structurally identical set of rules are given to ~9 years olds but couched in the language of permission, the children are able to pass with high probability. Stating the rules in terms of what the individual has experience with (or altering the linguistic phrasing) significantly increases the probability of solving much more than adjusting the age. So we have that on one hand, people develop capacities sooner (and more unevenly) than his theory supposed and that on another, some stages of reasoning aren't ever reached.

amasad is wrong to imply that the field has not progressed beyond the ideas of Piaget. Although, people do often get the important parts of Papert's ideas wrong by focusing too much on the computer part of computer-based learning. The computer should be a means to an end, a tool to help the learner explore more possibilities, make the abstract more graspable and amplify one's ability to ask better questions.