Open innovation describes the process of harnessing the distributed and collective intelligence of crowds. It is based on a number of principles including: collaboration, sharing, self-organisation, decentralisation, transparency of process and plurality of participants. The term was first used by Henry Chesbrough to describe a new model of product development based on the free flow of information and ideas across departments and organisations. It has taken on a wider meaning and application thanks to the advent of the internet which has enabled large numbers of people to interact and participate at a relatively low cost. Over the last few decades, there has been an explosion of methods designed to tap public imagination and ideas, perhaps in part a reaction against excessive deference to professions, and the idea that the expert knows best. Many of these methods have been greatly helped by the ability of the web to draw in a far wider range of people and ideas.