Preface

This special issue of the Journal on Multimodal User Interfaces collects a variety of papers dealing with multimodal corpora. Developing a multimodal corpus involves the recording, annotation and analysis of several communication modalities such as speech, hand gesture, facial expression, body posture, etc. As many research areas are moving from focused but single modality research to fully-fledged multimodality research, multimodal corpora are becoming a core research asset and an opportunity for an interdisciplinary exchange of ideas, concepts and data. The number of publicly available multimodal corpora is constantly growing as is the interest in studying multimodal communication by machines and through machines. This is a very positive trend, since the availability of large annotated multimodal corpora in different application domains, and for different languages, is a necessary prerequisite for the development of innovative, intelligent and flexible multimodal user interfaces.peer-reviewe