Manfred Tscheligi

Paper prototyping - what is it good for?: a comparison of paper- and computer-based low-fidelity prototyping

This study investigated the differences between computer-based and paper-based low-fidelity prototypes. It researched whether subjects confronted with these two kinds of prototypes differ in their willingness to criticize a system and to give suggestions for its improvement. The chosen approach was an empirical study including test sessions using both kinds of prototypes. Quantitative and qualitative methods were applied to measure and to explain possible differences.

Semantically structured tag clouds: an empirical evaluation of clustered presentation approaches

Tag clouds have become a frequently used interaction technique in the web. Recently several approaches to present tag clouds with the tags semantically clustered have been proposed. However, it remains unclear whether the expected gains in performance and advantages in interaction actually can be realized as no empirical evaluations of such approaches are available yet. In this paper we describe a series of experiments designed to evaluate the effects of semantic versus alphabetical and random arrangements of tags in tag clouds. The results of our work indicate that semantically clustered tag clouds can provide improvements over random layouts in specific search tasks and that they tend to increase the attention towards tags in small fonts compared to other layouts. Also, semantically structured tag clouds were preferred by about half of the users for general search tasks. Tag cloud layout does not seem to influence the ability to remember tags.

Towards Autonomous Cars: The Effect of Autonomy Levels on Acceptance and User Experience

Surveys [8] show that people generally have a positive attitude towards autonomous cars. However, these studies neglect that cars have different levels of autonomy and that User Acceptance (UA) and User Experience (UX) with autonomous systems differ with regard to the degree of system autonomy. The National Highway Traffic Safety Administration (NHTSA) defines five degrees of car autonomy which vary in the penetration of cars with Advanced Driver Assistance Systems (ADAS) and the extent to which a car is taken over by autonomous systems. Based on these levels, we conducted an online-questionnaire study (N = 336), in which we investigated how UA and UX factors, such as Perceived Ease of Use, Attitude Towards using the system, Perceived Behavioral Control, Behavioral Intention to use a system, Trust and Fun, differ with regard to the degree of autonomy in cars. We show that UA and UX are highest in levels of autonomy that already have been deployed in modern cars. More specifically, perceived control and fun decrease continuously with higher autonomy. Furthermore, our results indicate that pre-experience with ADAS and demographics, such as age and gender, have an influence on UA and UX.

A methodological variation for acceptance evaluation of Human-Robot Interaction in public places

Several variations of methodological approaches are used to study the social acceptance in human-robot interaction. Due to the introduction of robots in the home, working practice and usage typically informing the design of new forms of technology are missing. Studying social acceptance in human-robot interaction thus needs new methodological concepts. We propose a so called breaching experiment with additional ethnographic observation to close this gap. To investigate the methodological concept we have been conducting a field trial on a public place. We gathered feedback using questionnaires, in order to estimate whether this method can be beneficially to evaluate social acceptance. We could show that breaching experiments can be a useful method to investigate social acceptance in the field.

Robots asking for directions: the willingness of passers-by to support robots

This paper reports about a human-robot interaction field trial conducted with the autonomous mobile robot ACE (Autonomous City Explorer) in a public place, where the ACE robot needs the support of human passers-by to find its way to a target location. Since the robot does not possess any prior map knowledge or GPS support, it has to acquire missing information through interaction with humans. The robot thus has to initiate communication by asking for the way, and retrieves information from passers-by showing the way by gestures (pointing) and marking goal positions on a still image on the touch screen of the robot. The aims of the field trial where threefold: (1) Investigating the aptitude of the navigation architecture, (2) Evaluating the intuitiveness of the interaction concept for the passers-by, (3) Assessing peoples willingness to support the ACE robot in its task, i.e. assessing the social acceptability. The field trial demonstrates that the architecture enables successful autonomous path finding without any prior map knowledge just by route directions given by passers-by. An additional street survey and observational data moreover attests the intuitiveness of the interaction paradigm and the high acceptability of the ACE robot in the public place.

Personalized Digital Television

This chapter presents the recommendation techniques applied in Personal Program Guide (PPG). This is a system generating personalized Electronic Program Guides for Digital TV. The PPGmanages a user model that stores the estimates of the individual user’s preferences for TV program categories. This model results from the integration of di¡erent preference acquisitionmodules that handle explicit user preferences, stereotypical information about TV viewers, and information about the user’s viewing behavior. The observation of the individual viewing behavior is particularly easy because the PPG runs on the set-top box and is deeply integrated with the TV playing and the video recording services o¡ered by that type of device.

Depth and breadth away from the desktop: the optimal information hierarchy for mobile use

The optimal way to structure information in hierarchies has occupied researchers for at least two decades. In the last few years, mobile devices added new challenges to this research: the limited screen size, navigation methods and data transfer rates make the search for the optimal information structure even more complex. In this paper an experiment is presented that investigates the usability of 4 different information hierarchies (46, 84, 163 and 642) on three mobile devices. It turns out that the narrow hierarchies (46 and 84) perform better than the broader hierarchies on the three devices. The experiment was repeated on two more occasions with the same participants to test expertise effects; the preference for narrow hierarchies did not change over the three occasions.

How much do you tell?: information disclosure behaviour indifferent types of online communities

Online communities of different types have become an important part of the internet life of many people within the last couple of years. Both research and business have shown interest in studying the possibilities and risks of these relatively new phenomena. Very controversial aspects of these communities are their implications and effects on privacy issues, as research has shown that users generally provide information rather freely on such communities. However, no systematic comparison of differences in information disclosure behavior considering different types of communities is available. Furthermore only few is known about the information disclosure behavior related to demographic variables, usage contexts and usage patterns. To better understand these aspects of online communities we conducted an online survey that questioned users of various popular online communities about their information disclosure behavior and usage patterns of these sites. More than 850 users responded to our questionnaire. In this paper we present the main results of the analysis and provide linear regression models that allow understanding the involved factors in detail.

Probing an agile usability process

In this paper we describe adaptations to the classical Extreme Programming (XP) process. The approach described integrates HCI (human computer interaction) instruments. The implemented HCI instruments are: user studies, extreme personas (a variation of the personas approach), usability expert evaluations, usability tests, and automated usability evaluations. By combining XP and UCD (user centered development) processes we take advantages of both approaches.

Usability and usage of iTV services: lessons learned in an Austrian field trial

How users experience interactive TV (iTV) is determined by various factors; usability is a major one. In industry, usability is often seen as the key element that determines acceptance of new technologies by users. We present some of the results of an MHP-based (Multimedia Home Platform) iTV field trial in Salzburg, Austria concerning usability issues and iTV usage. We give an introduction to the field trial and an overview of its methods to ensure usability of iTV services and to measure their use. We present results from a usability test, give design recommendations, and discuss whether using iTV is an active or a passive user experience.