Constructionism asserts that learning is particularly effective when constructing something for others to experience. This can be anything from a spoken sentence or an internet posting, to more complex artifacts like a painting, a house or a software package.
For example, you might read this page several times and still forget it by tomorrow - but if you were to try and explain these ideas to someone else in your own words, or produce a slideshow that explained these concepts, then it's very likely you'd have a better understanding that is more integrated into your own ideas. This is why people take notes during lectures (even if they never read the notes again).
