The idea that learners construct meaning, of course, is the Constructivism of Jean Piaget. Constructivism talks about the invisible construction of ideas, and relations among ideas, within the mind of the learner. Constructionism adds to that the idea that /external/ construction of real artifacts is a powerful means to achieve Piaget's internal construction of understanding.
If knowledge is constructed by each learner, then creativity is a constant requirement. It's easy to underestimate the creative energy that every learner must put into the task of learning even seemingly simple matters of fact. This year's Constructionism conference takes learner creativity as its central theme.
Constructionism 2014 will be the third conference under that name, but building on the 27-year tradition of biennial Eurologo conferences established by the European Logo community. Logo is the computer programming language for learners in which the constructionist approach was first developed.