Interesting information on constructivist learning theories:
http://en.wikipedia.org/wiki/Constructivism_%28learning_theory%29#Constructivist_theory
History
In past centuries constructivist ideas were not widely valued due to the perception that children's play was seen as aimless and of little importance. Jean Piaget did not agree with these traditional views, however. He saw play as an important and necessary part of the student's cognitive development and has provided scientific evidence for his views. Today, constructivist theories are influential throughout much of the so-called informal learning sector. One example is the Investigate Centre at the Natural History Museum, London. Here visitors can engage in open ended investigations of real natural history specimens reaching towards self selected goals.Some historical figures who influenced constructivism:
Immanuel Kant 1724-1804
Jean-Jacques Rousseau, who strongly influenced modern educational theory through his book Emile: Or, On Education
John Dewey
Jerome Bruner
Constructivist theory
Formalization of the theory of constructivism is generally attributed to Jean Piaget, who articulated mechanisms by which knowledge is internalized by learners. He suggested that through processes of accommodation and assimilation, individuals construct new knowledge from their experiences. Assimilation occurs when individuals' experiences are aligned with their internal representation of the world. They assimilate the new experience into an already existing framework. Accommodation is the process of reframing one's mental representation of the external world to fit new experiences. Accommodation can be understood as the mechanism by which failure leads to learning. When we act on the expectation that the world operates in one way and it violates our expectations, we often fail. By accommodating this new experience and reframing our model of the way the world works, we learn from the experience of failure.
It is important to note that constructivism itself does not suggest one particular pedagogy. In fact, constructivism describes how learning happens, regardless of whether the learner is leveraging their experiences to understand a lecture or attempting to design a model airplane. In both cases, the theory of constructivism suggests that learners construct knowledge. Constructivism as a description of human cognition is often confused with pedagogic approaches that promote learning by doing.

Social constructivism
In recent decades, constructivist theorists have extended the traditional focus on individual learning to address collaborative and social dimensions of learning. It is possible to see social constructivism as a bringing together of aspects of the work of Piaget with that of Bruner and Vygotsky (Wood 1998: 39).