Christian Stickel

Emotion Detection: Application of the Valence Arousal Space for Rapid Biological Usability Testing to Enhance Universal Access

Emotion is an important mental and physiological state, influencing cognition, perception, learning, communication, decision making, etc. It is considered as a definitive important aspect of user experience (UX), although at least well developed and most of all lacking experimental evidence. This paper deals with an application for emotion detection in usability testing of software. It describes the approach to utilize the valence arousal space for emotion modeling in a formal experiment. Our study revealed correlations between low performance and negative emotional states. Reliable emotion detection in usability tests will help to prevent negative emotions and attitudes in the final products. This can be a great advantage to enhance Universal Access.

The XAOS metric: understanding visual complexity as measure of usability

The visual complexity of an interface is a crucial factor for usability, since it influences the cognitive load and forms expectations about the subjacent software or system. In this paper we propose a novel method that uses entropy, structure and functions, to calculate the visual complexity of a website. Our method is evaluated against a well known approach of using the file size of color jpeg images for determining visual complexity. Both methods were applied on a dataset consisting of images of 30 different websites. These websites were also evaluated with a web survey. We found a strong correlation for both methods on subjective ratings of visual complexity and structure. This suggests both methods to be reliable for determination of visual complexity.

A Study on the Compatibility of Ubiquitous Learning (u-Learning) Systems at University Level

Graz University of Technology has a long tradition in the design, development and research of university wide Learning Management Systems (LMS). Inspired by the iPhone Style, the available system has now been extended by the addition of a mobile viewer, which grants the student mobile accessibility to all available online content. In this paper, we report on the lessons learned within a study on user experience with this specially designed LMS mobile viewer. The User Experience (UX) was measured by application of a 26 item questionnaire including the six factors Attractiveness, Perspicuity, Efficiency, Dependability, Stimulation and Novelty, according to Laugwitz et al. (2008). The results showed high rates of acceptance, although the novelty of our approach received a surprisingly low rating amongst the novice end users.

iPhone/iPad human interface design

In this tutorial, we will present the Human Interface Guidelines for both iPhone and iPad and offer hands-on experience in designing user interfaces for these devices. We will also discuss how to integrate the guidelines in higher education and give examples from our lecture on iPhone application development. The goal of the tutorial is to provide the participants with a basic understanding of the iPhone Human Interface Guidelines and enable them to review and design iPhone apps according to the standards.

Intuitive E-Teaching by Using Combined HCI Devices: Experiences with Wiimote Applications

The wide availability of game based technologies and sophisticated e-Learning possibilities creates new demands and challenges on Human---Computer Interaction and Usability Engineering (HCI&UE). Solid research in HCI must support improvement in learning ability and creativity for both teachers and students. According to recent market surveys the Wii remote controller or Wiimote is currently more wide spread than standard Tablet PCs and is the most used computer input device worldwide. As a collection of many sensors, also including Bluetooth technology, accelerometers and IR sensors, Wiimote is of great interest for HCI experiments, especially in the area of e-Learning and e-Teaching. In this paper, we present results gained from the investigation of the potential of Wiimote as both a standard input device --- such as mouse or presenter --- and as a gesture and finger tracking sensor. We demonstrate, on the basis of examples from e-Teaching, how easily everyday gestures can be interpreted in regular computer applications utilizing Wiimotes hardware modules and some additional software modules.

Seeing the System through the End Users' Eyes: Shadow Expert Technique for Evaluating the Consistency of a Learning Management System

Interface consistency is an important basic concept in web design and has an effect on performance and satisfaction of end users. Consistency also has significant effects on the learning performance of both expert and novice end users. Consequently, the evaluation of consistency within a e-learning system and the ensuing eradication of irritating discrepancies in the user interface redesign is a big issue. In this paper, we report of our experiences with the Shadow Expert Technique (SET) during the evaluation of the consistency of the user interface of a large university learning management system. The main objective of this new usability evaluation method is to understand the interaction processes of end users with a specific system interface. Two teams of usability experts worked independently from each other in order to maximize the objectivity of the results. The outcome of this SET method is a list of recommended changes to improve the user interaction processes, hence to facilitate high consistency.

Usability Metrics of Time and Stress - Biological Enhanced Performance Test of a University Wide Learning Management System

This paper describes the modification and outcome of a performance test applied to a university wide learning management system under realistic conditions to identify usability problems and to compare measures such as success rate, task time and user satisfaction with requirements. Two user groups with 20 test users each took part in this study. During the whole test psycho-physiological parameters of the test persons were monitored and recorded, in order to find event related stress symptoms. Modifications of the original test allowed a faster analysis of relevant quantitative metrics and the collection of qualitative information.

Useful oblivion versus Information Overload in e-learning examples in the context of Wiki systems

Information overload refers to the state of having too much information to make a decision or remain informed about a topic. We present a novel approach of filtering, adapting and visualizing content inside a Wiki knowledge base. Thereby we follow the question of how to optimize the process of learning, with respect to shorter time and higher quality, in face of increasing and changing information. Our work adopts a consolidation mechanism of the human memory, in order to reveal and shape key structures of a Wiki hypergraph. Our hypothesis so far is that visualization of these structures enables a more efficient learning.

Shadow expert technique (SET) for interaction analysis in educational systems

This paper describes a novel usability method called Shadow Expert Technique (SET), which was applied on the learning management system of the Graz University of Technology in two different trials, with focus on consistency and visual complexity. This is the summary of the development of this new method and the approach to generalize it as a new way to get deeper insight into interaction processes.

The modeling of harmonious color combinations for improved usability and UX

This study compares three different models for the calculation and prediction of harmonious color combinations. Therefore a dataset of user rated color combinations was taken from a large online database. The user rating was compared to the outcome of the three models on this dataset in order to test the performance of the models. The first model based on the idea that color combinations are more pleasing the greater their difference in brightness. The second model is a slightly modified version of Ou & Lou (2006) using chromatic difference, lightness sum, lightness difference and hue effect. The last model was invented by us and is based on an experiment of Polzella & Montgomery (1993). From the outcome of their experiment we generated a lookup table for single color rating. This rating is then used in a formula, which is able to evaluate the color harmony for color combinations up to five colors. This model also performed best in the overall comparison between the three color harmony models.