"Sitting too close to the screen can be bad for your ears": A study of audio-visual location discrepancy detection under different visual projections

In this work, we look at the perception of event locality under conditions of disparate audio and visual cues. We address an aspect of the so called “ventriloquism effect” relevant for multi-media designers; namely, how auditory perception of event locality is influenced by the size and scale of the accompanying visual projection of those events. We observed that recalibration of the visual axes of an audio-visual animation (by resizing and zooming) exerts a recalibrating influence on the auditory space perception. In particular, sensitivity to audio-visual discrepancies (between a centrally located visual stimuli and laterally displaced audio cue) increases near the edge of the screen on which the visual cue is displayed. In other words,discrepancy detection thresholds are not fixed for a particular pair of stimuli, but are influenced by the size of the display space. Moreover, the discrepancy thresholds are influenced by scale as well as size. That is, the boundary of auditory space perception is not rigidly fixed on the boundaries of the screen; it also depends on the spatial relationship depicted. For example,the ventriloquism effect will break down within the boundaries of a large screen if zooming is used to exaggerate the proximity of the audience to the events. The latter effect appears to be much weaker than the former

The impact of cognitive styles on perceptual distributed multimedia quality

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2003 John Wiley & Sons, Inc.Multimedia technology has been widely used in web-based instruction, but previous studies have indicated that individual differences, especially cognitive styles, have significant effects on users’ preferences with respect to presentation of multimedia content. However, such research has thus far neglected to examine the effect of cognitive styles on users’ subjective perceptions of multimedia quality. This study aims to examine the relationships among users’ cognitive styles, the multimedia Quality of Service (QoS) delivered by the underlying network, and Quality of Perception (QoP), which encompasses user levels of enjoyment and understanding of the informational content provided by multimedia material. Accordingly, 132 users took part in an experiment in which they were shown multimedia video clips presented with different values of two QoS parameters (frame rate and colour depth). Results show that, whilst the two QoS parameters do not impact user QoP, multimedia content and dynamism levels significantly influence the user understanding and enjoyment component of QoP

Human-computer interaction : Guidelines for web animation

Human-computer interaction in the large is an interdisciplinary area which attracts researchers, educators, and practioners from many differenf fields. Human-computer interaction studies a human and a machine in communication, it draws from supporting knowledge on both the machine and the human side. This paper is related to the human side of human-computer interaction and focuses on animations. The growing use of animation in Web pages testifies to the increasing ease with which such multimedia features can be created. This trend shows a commitment to animation that is often unmatched by the skill of the implementers. The paper presents a set of guidelines and tips to help designers prepare better and more effective Web sites. These guidelines are drawn from an extensive literature survey

Gaze Behavior, Believability, Likability and the iCat

The iCat is a user-interface robot with the ability to express a range of emotions through its facial features. This paper summarizes our research whether we can increase the believability and likability of the iCat for its human partners through the application of gaze behaviour. Gaze behaviour serves several functions during social interaction such as mediating conversation flow, communicating emotional information and avoiding distraction by restricting visual input. There are several types of eye and head movements that are necessary for realizing these functions. We designed and evaluated a gaze behaviour system for the iCat robot that implements realistic models of the major types of eye and head movements found in living beings: vergence, vestibulo ocular reflexive, smooth pursuit movements and gaze shifts. We discuss how these models are integrated into the software environment of the iCat and can be used to create complex interaction scenarios. We report about some user tests and draw conclusions for future evaluation scenarios

Use interactive multimedia to improve your programming course

This paper reports first year students’ experiences with multimedia-based learning for programming and its influence on students obtained from two case studies at Napier and Brunel universities. Engineering students at the universities have taken programming courses from their first year and many have showed difficulties in their learning. The main reason is that it is a very abstract domain, which means that both lecturers and students can have difficulties in explaining and understanding abstract concepts verbally. Considering the strengths of Interactive Multimedia(IMM), i.e. interactivity and visualisation, we decided to use it to improve students’ learning. An empirical study was planned and IMM materials were designed for this. A trial and two case studies were carried out from December 2000 to June 2001. The designed materials were integrated into the curriculum as a teaching aid and self-guided learning materials. The data gathered from the case studies indicated that many students felt the multimedia-based learning helped their understanding of the programming concepts, and some became very motivated in programming. Also, using the interactive multimedia materials for both teaching and learning enhanced students’ learning experience. At last, we found educating both lecturers and students on what is multimedia-based learning prior to a course can increase its effectiveness

A survey of real-time crowd rendering

In this survey we review, classify and compare existing approaches for real-time crowd rendering. We first overview character animation techniques, as they are highly tied to crowd rendering performance, and then we analyze the state of the art in crowd rendering. We discuss different representations for level-of-detail (LoD) rendering of animated characters, including polygon-based, point-based, and image-based techniques, and review different criteria for runtime LoD selection. Besides LoD approaches, we review classic acceleration schemes, such as frustum culling and occlusion culling, and describe how they can be adapted to handle crowds of animated characters. We also discuss specific acceleration techniques for crowd rendering, such as primitive pseudo-instancing, palette skinning, and dynamic key-pose caching, which benefit from current graphics hardware. We also address other factors affecting performance and realism of crowds such as lighting, shadowing, clothing and variability. Finally we provide an exhaustive comparison of the most relevant approaches in the field.Peer ReviewedPostprint (author's final draft

Getting the message across : ten principles for web animation

The growing use of animation in Web pages testifies to the increasing ease with which such multimedia components can be created. This trend indicates a commitment to animation that is often unmatched by the skill of the implementers. The present paper details a set of ten commandments for web animation, intending to sensitise budding animators to key aspects that may impair the communicational effectiveness of their animation. These guidelines are drawn from an extensive literature survey coloured by personal experience of using Web animation packages. Our ten principles are further elucidated by a Web-based on-line tutorial

Modulating the Non-Verbal Social Signals of a Humanoid Robot

In this demonstration we present a repertoire of social signals generated by the humanoid robot Pepper in the context of the EU-funded project MuMMER. The aim of this research is to provide the robot with the expressive capabilities required to interact with people in real-world public spaces such as shopping malls-and being able to control the non-verbal behaviour of such a robot is key to engaging with humans in an effective way. We propose an approach to modulating the non-verbal social signals of the robot based on systematically varying the amplitude and speed of the joint motions and gathering user evaluations of the resulting gestures. We anticipate that the humans' perception of the robot behaviour will be influenced by these modulations