Writers on education have frequently contrasted knowledge and understanding as educational aims. I shall be prepared to defend the view that this contrast can mislead us in our thinking about education, and can direct our attention away from facts which are important to take into account in the evaluation of educational procedures.

The development of Web 2.0 has opened new opportunities for teaching and learning - an entire ecology of online learning. This ecology has not previously been systematically investigated. This book offers the first comprehensive conceptual map for this territory.