Fusion of children's speech and 2D gestures when conversing with 3D characters

Most existing multi-modal prototypes enabling users to combine 2D gestures and speech input are task-oriented. They help adult users solve particular information tasks often in 2D standard Graphical User Interfaces. This paper describes the NICE Andersen system, which aims at demonstrating multi-modal conversation between humans and embodied historical and literary characters. The target users are 10–18 years old children and teenagers. We discuss issues in 2D gesture recognition and interpretation as well as temporal and semantic dimensions of input fusion, ranging from systems and component design through technical evaluation and user evaluation with two different user groups. We observed that recognition and understanding of spoken deictics were quite robust and that spoken deictics were always used in multi-modal input. We identified the causes of the most frequent failures of input fusion and suggest possible improvements for removing these errors. The concluding discussion summarises the knowledge provided by the NICE Andersen system on how children gesture and combine their 2D gestures with speech when conversing with a 3D character, and looks at some of the challenges facing theoretical solutions aimed at supporting unconstrained speech/2D gesture fusion.