Introduction: The Challenge of Ubiquitous Knowledge Discovery

In the past, the development of machine learning approaches was to some extent motivated by the availability of data and increased computational power. Ubiquitous computing bears the promise of stimulating a similar leap forward. Small devices can now be installed in many places, mobile and wearable devices enable registration of large amounts of information, thus generating a wide range of new types of data for which new learning and discovery methods are needed, far beyond existing ones.