Sascha Mahlke

Usability, aesthetics and emotions in human–technology interaction

In the past, research on human–technology interaction has almost exclusively concentrated on aspects of usefulness and usability. Despite the success of this line of research, its narrow perspective has recently become a target for criticism. To explain why people prefer some systems over others, factors such as aesthetic qualities and emotional experiences play an important role in addition to instrumental aspects. In the following, we report three experiments that illustrate the importance of such factors. In the first experiment, we study the role of emotions in human–technology interaction by using Scherers (1984) component theory of emotions as a theoretical foundation. A combination of methods is derived from that theory and employed to measure subjective feelings, motor expressions, physiological reactions, cognitive appraisals, and behaviour. The results demonstrate that the manipulation of selected system properties may lead to differences in usability that affect emotional user reactions. The s...

Factors influencing the experience of website usage

The present study examines the role of subjectively preceived factors of the experience of website usage in forming an intention to use a website. An integrative research model is presented and tested empirically. It includes the following four aspects of experience: perceived usefulness, ease of use, hedonic quality and visual attractiveness. The two main research questions are: (1) Are these aspects four subjectively independently preceived aspects of website interaction? and (2) Is the intention to use formed by combining and weighting these four experience aspects and if so, which weights are assigned to the respective aspects.The results suggest that all four aspects of experience can be independently perceived by the user and contribute all with different weights to the intention to use the website.

Evaluation of Six Night Vision Enhancement Systems: Qualitative and Quantitative Support for Intelligent Image Processing

Objective: An evaluation study was conducted to answer the question of which system properties of night vision enhancement systems (NVESs) provide a benefit for drivers without increasing their workload. Background: Different infrared sensor, image processing, and display technologies can be integrated into an NVES to support nighttime driving. Because each of these components has its specific strengths and weaknesses, careful testing is required to determine their best combination. Method: Six prototypical systems were assessed in two steps. First, a heuristic evaluation with experts from ergonomics, perception, and traffic psychology was conducted. It produced a broad overview of possible effects of system properties on driving. Based on these results, an experimental field study with 15 experienced drivers was performed. Criteria used to evaluate the development potential of the six prototypes were the usability dimensions of effectiveness, efficiency, and user satisfaction (International Organization for Standardization, 1998). Results: Results showed that the intelligibility of information, the easiness with which obstacles could be located in the environment, and the position of the display presenting the output of the system were of crucial importance for the usability of the NVES and its acceptance. Conclusion: All relevant requirements are met best by NVESs that are positioned at an unobtrusive location and are equipped with functions for the automatic identification of objects and for event-based warnings. Application: These design recommendations and the presented approach to evaluate the systems can be directly incorporated into the development process of future NVESs.

Aesthetic and Symbolic Qualities as Antecedents of Overall Judgements of Interactive Products

Quality aspects of an interactive system that address user needs that go beyond users’ instrumental needs are one important area for user experience research. Two categories of non-instrumental qualities seem to be important: aesthetic and symbolic aspects. In an explorative study the role of different dimensions of non-instrumental quality and their influence on overall judgements, like beauty or goodness of an interactive product, were studied. Four digital audio players were used to get information on users’ perception of instrumental and non-instrumental quality perceptions as well as overall judgements. The results show the importance of various non-instrumental quality aspects and point out the need for further research.

Studying user experience with digital audio players

Several attempts have been made to broaden the traditional focus on the efficient achievement of goals and incorporate a fuller understanding of additional aspects of the user experience. These approaches are especially interesting for the area of entertainment computing, where the efficient completion of tasks is not the main focus. The presented research project investigates the role of non-instrumental aspects as hedonics and aesthetics and their interplay with emotions in shaping the user experience. After introducing an integrative model, a first application of the approach in a study of user experience with digital audio players is described. The findings show that this approach offers a wealth of insights that can be used to improve product design from a user perspective.