A computer based system to design expressive avatars

Avatars are used in different contexts and situations: e-commerce, e-therapy, virtual worlds, videogames,collaborative online design... In this context, a good design of an avatar may improve the user experience. The ability of controlling the way an avatar convey messages and emotions is capital. In this work, a procedure to design avatar faces capable of conveying to the observer the most suitable sensations according to a given context is developed. The proposed system is based on a combination of genetic algorithms and artificial neural networks whose training is based on perceptual human responses to a set of faces.Diego-Mas, JA.; Alcaide Marzal, J. (2015). A computer based system to design expressive avatars. Computers in Human Behavior. 44:1-11. doi:10.1016/j.chb.2014.11.027S1114

Multimodal e-feedback: An Empirical Study

This thesis investigated the applicability of unique combinations of multimodal metaphors to deliver different types of feedback. The thesis evaluates the effect of these combinations on the usability of electronic feedback interfaces and on the users’ engagement to learning. The empirical research described in this thesis consists of three experimental phases. In the first phase, an initial experiment was carried out with 40 users to explore and compare the usability and users’ engagement of facially animated expressive avatars with text and natural recorded speech, and text with graphics metaphors. The second experimental phase involved an experiment conducted with 36 users to investigate user perception of feedback communicated using avatar with facial expressions and body gestures, and voice expressions of synthesised speech. This experiment also aimed at evaluating the role that an avatar could play as virtual tutor in e-feedback interfaces by comparing the usability and engagement of users using three different modes of interaction: video with tutor that presented information with facial expressions, synthesised spoken messages supported with text, and avatars with facial expressions and body gestures. The third experimental phase, introduced and investigated a novel approach to communicate e-feedback that was based on the results of the previous experiments. This approach involved speaking avatars to deliver feedback with the aid of earcons, auditory icons, facial expressions and body gestures. The results demonstrated the usefulness and applicability of the tested metaphors to enhance e-feedback usability and to enable users to attain a better engagement with the feedback. A set of empirically derived guidelines for the design and use of these metaphors to communicate e-feedback are also introduced and discussed.Saudi Higher Education Ministr