On mobile devices, vibrotactile messages are a common way to give feedback to the user. They might be a less obtrusive means to communicate information about the system status compared to auditory feedback. Much research has focused on the possibilities to perceive and discriminate different vibrotactile messages, less regarding her contentual interpretation. We describe a series of two studies. Aim of the pilot study was to find meaningful vibrotactile messages of which we then wanted to investigate the affective impression and functional connotation on a mobile device within varying staged contexts. Results show that the affective impression of those so-called Tactons is independent of the context. Moreover, we observed a relation between ratings of affective quality and functional applicability. We conclude that tactile feedback messages are unobtrusive, but have to be designed carefully to convey their intended meaning in a working context as well as in a leisure time situation. Tactile feedback. Mobile context. Affective impression.

To give feedback on mobile devices, sound is commonly used in different ways. Much research has focused on the learnability and user performance with systems that have audio feedback. But so far, there is no standardized method to evaluate the subjective quality of auditory feedback messages. We describe a study to investigate the affective impression of short audio feedback on mobile devices and their functional connotation in three different contexts. Results show that context influences the affective impression of sounds and that there is a relation between ratings according affective quality and functional applicability. We conclude that sounds can be unobtrusive, but still convey their intended meaning in a working context as well as in a leisure time situation without being perceived as disturbing.

Sound is a common means to give feedback on mobile devices. Much research has been conducted to examine the learnability and user performance with systems that provide audio feedback. In many cases a training period is necessary to understand the meaning of a specific feedback, because their functional connotation may be ambiguous. Additionally, no standardized evaluation method to measure the subjective quality of these messages has been established; especially regarding the affective quality of feedback sounds. The authors describe a series of experiments to investigate the affective impression of audio feedback on mobile devices as well as their functional meaning under varying contexts prototypical for mobile phone usage. Results indicate that context influences the emotional impression and that there is a relation between affective quality and functional appropriateness. These findings confirm that emotional stimuli are suitable as feedback messages in the context of mobile HCI and that context matters for the affective quality of sounds emitted by mobile phones.

Usability evaluation of multimodal systems is a complex issue. Multimodal systems provide multiple channels to communicate with the system. Thus, the single modalities as well as their combination have to be taken into account. This paper aims to investigate how ratings of single modalities relate to the ratings of their combination. Therefore a usability evaluation study was conducted testing an information system in two unimodal versions and one multimodal version. Multiple linear regression showed that for overall and global judgments ratings of the single modalities are very good predictors for the ratings of the multimodal system. For separate usability aspects (e.g. hedonic qualities) the prediction was less accurate.

No abstract