Avatars at Work and Play (p.26-35)

1. Avatars at Work and Play (p.26-35) By Jennifer Lee

2. Behavioral Fidelity: Exploring the impact of Eye Gaze • The experiment was designed to investigate the importance of eye gaze in humanoid avatars representing people engaged in conversation. • The experiment was conducted using a video-tunnel setup and was therefore not immersive, but it was done deliberately to isolate gaze behavior from any other factors, such as spatial, gestural or postural cues that might have confounded results. • Participants saw a face-on head-and shoulders view of the avatar representing their conversation partner.

3. Cont. • An avatar with random head and eye movement was compared to a visually identical “inferred gaze” avatar that combined simple head-tracking with “while speaking” and “while listening” eye animations inferred from the audio stream. • The design of these eye animations was informed by social psychology research on the differences in gaze patterns while speaking and while listening in face-to-face interaction. • The researcher then compared both avatar’s condition to video (with audio) and audio-only baseline conditions. • The goals of this experiment was to test whether an avatar with minimal behavioral fidelity could contribute to the perceived quality of communication between two remote users and to examine the role of gaze.

4. In the random gaze condition, both the head and eye movements were designed to appear natural but were in no way tied to the content or flow of conversation. • The inferred gaze avatar, the head movements were tracked using a single sensor attached to the headphones. • The eye movements were inferred from the audio stream. • the inferred gaze avatar significantly outperformed the random gaze avatar on all measures, indicating that an avatar whose behaviors are related to the conversation can present a marked improvement over an avatar that merely exhibits liveliness.

5. Visual and Behavioral: Exploring the Impact of Eye Gaze and Photorealism • In the experiment of the Eye Gaze, the participants were shown a limited, head-and-shoulders view of the virtual human, and the spatial relationships was fixed by the 2D nature of the interaction. • It left open the question of how these gaze models might hold up in an immersive situation where participants are able to wander freely around a shared space, and where they can interact with a full-body, life-size avatar. • One assumption made by several researchers is that convincing behaviour is a higher priority than realistic appearance in the development of expressive avatars. • They tested this assumption by investigating the impact of the (higer-fidelity) inferred gaze model with the (lower fidelity) random gaze model on avatars whose appearance represented different levels of photorealism.

6. Cont. • Experiment: • Participants were represented to their conversation partner as a life-size avatar Since one of the central aims of this experiment was to disambiguate the impact of head-tracking and the inferred eye animations, participants’ heads were tracked in all conditions, and only the eye animations were varied. The random gaze eye animations were identical to the first eye gaze experiment, but the inferred gaze animations were refined based on newly published information.

7. Key words • Gaze fidelity: the sense of mutual gaze with the conversation partner. • Avatar fidelity: the degree to which the avatar’s appearance and behaviour were seen to be realistic. • Social-copresence: consisting of the following subcomponents. • General copresence: the sense of being in the same space as the conversation partner. • Personal contact: the degree of personal contact experienced with the partner.

8. Cont. • The impact of the gaze model is different depending on which type of avatar is used. • The higher realism avatar the inferred gaze behaviour increases perceived effectiveness for several response measures. • For the lower realism avatar, the inferred gaze behaviour reduces effectiveness. • With respect to eye gaze, low fidelity appearance demands low fidelity behaviour and higher fidelity appearance demands a more realistic behaviour model. • The caveat is that there should be some consistency between visual and behavioural realism, since the lower realism avatar did not benefit from the higher realism, inferred gaze model. • The first eye gaze study indicate that avatar fidelity does not work in isolation in shaping interaction experiences. Even by adding liveliness to the avatar’s behavioural does not add value to the interaction.

9. Conclusions and Future Work • Increasing the expressive potential of avatars involves significant challenges. In terms of their appearance, the tension between realism and real time means that photorealism comes at the expense of unwanted delays to real-time communication. • Full manual control of avatar behaviour would entail an unacceptable level of cognitive load. • Full tracking can be expensive and invasive, and may not be desirable in a medium that is prized for the control it affords over visual identity. • The findings from the experiment on eye gaze and photorealism indicate that the effect of identical eye animations changes in relation to the avatar’s appearance. • The higher realism avatar benefited from the higher fidelity inferred gaze animations, whereas the opposite was true for the lower realism avatar. • The conclusion is that the impact of behaviour is not independent of appearance and points to a more complex picture than was previously envisaged.

10. Cont. • Avatars are computer generated and therefore, unlike video, free us from the need to present a faithful visual replica of real places or real people. Like masks, they preserve our visual anonymity and open up the possibility for new and potentially different forms of interactions.