Force feedback and shape change are modalities with a growing application potential beyond the more traditional GUIs. We present two studies that explored the effect of these modalities on the emotional experience when interacting with an intelligent thermostat. The first study compared visual feedback, force feedback, and a combination of force feedback and shape change. Results indicate that force feedback correlates to experienced dominance during interaction, while shape change mainly affects experienced arousal. The second study explored how force feedback and shape change could communicate affective meaning during interaction with the thermostat through a co-design study. Participants designed the thermostat behavior for three scenarios supporting energy savings. Results suggest that despite their abstractness, force feedback and shape change convey affective meaning during the user-system dialogue. The findings contribute to the design of intelligible and intuitive feedback.

Although interfaces can adapt to users' behavior only little empirical evidence has been reported about their capability to influence people's emotions. The goal of this study is to explore the influence of haptic force feedback on the emotional experience in a linear sliding movement. We varied force feedback behaviors designed for a motorized slider in a controlled experiment. The slider presented three behaviors, named as counteractive, assistive, and no behavior while participants were exposed to affective imagery varying in valence. The results showed that under different emotions (positive, negative, neutral), people experience small differences in dominance and valence between the force feedback behaviors. A counteractive force feedback seems to increase the feeling of control regarding unpleasant stimuli, while providing an assistive force feedback reduced the level of dominance in case of pleasant stimuli. Our study contributes new understanding of how adaptive feedback influence user's emotions to support design in this field.

'Viewing while commuting' is a typical use case for mobile video. However, experimental and behavioral influences of watching three-dimensional (3D) video in vibrating vehicles have not been widely researched. The goal of this study is 1) to explore the influence of video presentation modes (two-dimensional and stereoscopic 3D) on the quality of experience and 2) to understand the nature of the movement patterns that users perform to maintain an optimal viewing position while viewing videos on a mobile device in three commuting contexts and in a controlled laboratory environment. A hybrid method for quality evaluation was used for combining quantitative preference ratings, qualitative descriptions of quality, situational audio/video data-collection, and sensors. The high-quality and heterogeneous audiovisual stimuli were viewed on a mobile device equipped with a parallax barrier display. The results showed that the stereoscopic 3D (S3D) video presentation mode provided more satisfying quality of experience than the two-dimensional presentation mode in all studied contexts. To maintain an optimal viewing position in the vehicles, the users moved the device in their hands to the directions around the vertical and the horizontal axes in a leaned sitting position. This movement behavior was guided by the contexts but not by the quality, indicating the general importance of these results for mobile video viewing in vibrating vehicles.

Reading of digital news on personal devices has dramatically increased. Parallel to new devices, novel services and content types are created forming new habits and experiences for readers. Previous research is limited in understanding temporal aspects of such users' experiences (UX). This study aims to understand UX of mobile news reading in a real context of use over one week in two different case studies. UX of digital replicas, browser optimized versions of digital news, and a novel media authentication method for news reading and ordering were explored with actual news readers (N=36) in field using their own tablets and personal computers. Data-collection included daily diaries with UX questionnaires, and retrospective interviews. The results showed that the studied forms of digital news and authentication method provided positive UX, and they were appealing for future digital news. UX also showed a tendency of improving over a time. The user's habits of reading digital news reflected the conventions of reading a print newspaper.

In this study, we applied a locally adaptive filtering in 3D DCT domain to 3 views as a preprocessing stage for encoding. Afterwards, these views were encoded and the decoded views were used by a Depth-Image-Based Rendering algorithm (DIBR) to produce virtual intermediate views. A stereopair at a suitable separation for viewing on a stereoscopic display was selected among the synthesized views. A large-scale subjective assessment of the selected synthesized stereopair was performed. A bitrate reduction of 9% on average and up to 21.8% was achieved with almost no penalties on subjective perceived quality.

Subjective quality evaluation is used to optimize the produced audiovisual quality from fundamental signal processing algorithms to consumer services. These studies typically follow the basic principles of controlled psychoperceptual experiments. However, when compromising compression and transmission parameters for consumer services, the ecological validity of conventional quality evaluation methods can be questioned. To tackle this, we firstly present a novel user-oriented quality evaluation method for mobile television in its usage contexts. Secondly, we present the results of an experiment conducted with 30 participants comparing acceptability and satisfaction of quality as well as goals of viewing in three mobile contexts and under four different residual transmission error rates, when the participants also performed simultaneous assessment tasks. Finally, we compare the results with a previous laboratory experiment. The studied error rates impacted negatively on all measured tasks with some contextual differences. Moreover, the evaluations were more favorable and less discriminate in the mobile contexts compared to the laboratory.

As in many digital telecommunications systems, the received data streams over Digital Video Broadcasting for Handhelds (DVB-H) may contain bursty transmission errors. The bursty error characteristics affect the end users' perceived audiovisual quality. This study examined the perceived unacceptability of instantaneous but noticeable audio, visual and audiovisual errors. The erroneous streams were generated from four popular television contents by applying three simulated error patterns with different error rates (1.7%, 6.9%, 13.8%) and error burst durations. Instantaneous unacceptability of errors was evaluated by 30 participants with simplified continuous assessment while watching the program content. The results show that with the two lowest error rates the audio errors were more unacceptable than video errors and with the highest error rate the visual and audiovisual errors become the most unacceptable.

Subjectively perceived video quality is a critical factor when adopting new mobile video applications. When video is used in mobile networks the most important requirements are related to low bitrates, framerates and the screen size of mobile device. In two tests we investigated the effects of codecs and combinations of audio and video streams with low bitrates and different contents on the perceived video quality of mobile devices. The first test showed that the codec H.264 produced the most satisfying video quality, but the quality was not high enough for the presentation of textual information. In the second test, the audio-video ratio 32/128kbps was found to be the most pleasant, but there were content dependent variations.