The following links contain information that you may find useful to broaden your understanding of "Constructivism". Each link contains a brief summary of what is found within it:
1. History of Constructivism: http://www.thirteen.org/edonline/concept2class/constructivism/index_sub4.html
The concept of constructivism has roots in classical antiquity, going back to Socrates's dialogues with his followers, in which he asked directed questions that led his students to realize for themselves the weaknesses in their thinking. The Socratic dialogue is still an important tool in the way constructivist educators assess their students' learning and plan new learning experiences.
2. History of Constructivism: http://halmedrano.com/527/foundations/index.html
In contrast to both behaviorism and early cognitivism, constructivism is not an objectivist theory in which "truth" is viewed as external to the learner, and the mind acts to process input from reality. The challenge posed by constructivism is that it presents a new view of how reality is perceived, and implies entirely new roles for teachers and students alike.
3. Constructivism in the Classroom http://www.sedl.org/scimath/compass/v01n03/
This is a whole online journal from Southwest Educational Development Laboratory that details Constructivism in the Classroom from several different perspectives.