Thanks all so much for your thoughful comments, indeed you helped me to learn about the subject in a true Contructivist maner.
Vygotsky' Constructivism theory is a valid and complete, however it is still a theory. What we need is to elaborate (contruct) a computational model to implement the Vygotsky'ZPD and scaffolding faithfully. Seymour and Papert have already attempt it using some approaches succesfuly to some extent, according to them : Seymour Papert on Constructivism and (Papert’s) Constructionism:
"The word with the v expresses the theory that knowledge is built by the learner, not supplied by the teacher. The word with the n expresses the further idea that happens especially felicitously when the learner is engaged in the construction of something external or at least sharable" (Papert, 1991, p.3). "
For almost all discipline (especially (software) engineering), where the learner engage in contructing objects, models, modules, tools, systems, artefacts either conceptual or physical. Their theory seems to be valid even not complete. They build effective software tools on it.
As I am interested mostly by building coursware dealing with algrithm design, compiler design, Fuzzy logic, Computational Intelligence, database design, software design, programming. Seymour and Papert approach is a promissing apprioach for me for the moment. To implement Vygotsky' Constructivism in a computational model is very hard; we need tight collaboration of psycologists, educationalists, computer and software scientists, a thing which beyond the reach of a conventional laboratory of a computer science. I am now more closer to the progressist school too.
Are we able to elaborate (contruct) a computational model to implement the Vygotsky'ZPD and scaffolding faithfully in terms of software tool or in terms of a Moodle coursware. Better is to start by asking Sir Martin Dougiamas . . .
Keep the good work and keep posting