Johann Schrammel

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.

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.

3D attention: measurement of visual saliency using eye tracking glasses

Understanding and estimating human attention in different interactive scenarios is an important part of human computer interaction. With the advent of wearable eye-tracking glasses and Google glasses, monitoring of human visual attention will soon become ubiquitous. The presented work describes the precise estimation of human gaze fixations with respect to its environment, without the need of artificial landmarks in the field of view, and being capable of providing attention mapping onto 3D information. It enables full 3D recovery of the human view frustum and the gaze pointer in a previously acquired 3D model of the environment in real time. The key contribution is that our methodology enables mapping of fixations directly into an automatically computed 3d model. This innovative methodology will open new opportunities for human attention studies during interaction with its environment, bringing new potential into automated processing for human factors technologies.

Tablet, gestures, remote control?: influence of age on performance and user experience with iTV applications

Due to recent development of TVs in the direction of highly interactive multimedia platforms, interactive TV (iTV) applications gain popularity. In terms of control possibilities a variety of input modalities have become available, though effects on performance and user experience of different age groups when controlling different iTV applications remain unclear. We present an empirical investigation comparing three input modalities (tablet, freehand gestures, remote) for controlling two iTV applications (Photo Browser, Nutrition Tracker) used by older and younger adults. Results show that all three independent variables had significant influence on performance, while we did not find influence of age or application on user experience. Overall tablet input based on a mirrored TV screen showed the best performance and was preferred by both age groups. Older adults were overall slower and showed a particularly large performance gap with the remote in comparison to younger adults.

FORE-Watch – the clock that tells you when to use: persuading users to align their energy consumption with green power availability

Besides saving energy, using it at the right time (i.e. when there is a supply surplus, and the power is produced by sustainable power sources such as hydroelectricity or wind) is an important possibility to achieve positive effects for the environment. To enable the user to align their behavior with the dynamics of the energy generation they need to be informed about the current status of power supply and grid capacity. Furthermore, to be able to plan their behavior and possibly delay or advance consumption activities to more proper moments they also need to have access to high-quality forecasts about the future status of green energy supply. In this paper we present an ambient display design solution based on a common watch that is optimized for providing this information in an unobtrusive, ambient and persuasive way. We present and discuss requirements identified by use of literature analysis, focus groups and end-user questionnaires, outline approaches to calculate basic power generation forecasts based on weather forecast data and present an ambient interface concept designed to meet the identified requirements. We conclude that the developed approach has high potential to support desired behavior changes, and that achieving acceptable accuracy levels for the generation forecast is feasible with relatively little effort.

Usability evaluations for multi-device application development three example studies

This paper discusses three example studies, that informed user interface guidelines, developed for a set of different classes of mobile devices. The results of these studies show answers to typical design problems arising during the development of mobile applications. Furthermore the studies are meant to be examples showing which kind of studies are required in order to develop a sufficient pool of user interface guidelines covering almost all sorts of mobile devices.

Attentional Behavior of Users on the Move Towards Pervasive Advertising Media

In this chapter we analyze the attention of users on the move towards pervasive advertising media. We report the findings of two multi-sensor eye tracking studies designed to provide a better understanding of the actual attentional behavior of users on the move in different public environments. In the first study 106 participants were equipped with eye tracking technology and asked to use public transportation vehicles equipped with information and advertising screens. In a second study 16 participants were asked to stroll through a shopping street for about 15 min, and during this time different indicators for their behavior and focus of attention (eye tracking, movement and pose tracking) were captured. Motion and pose data was correlated with eye tracking data to identify typical patterns of attention. We report the results of these studies, then discuss the implications of the main findings for pervasive advertising and finally reflect on the used research methodology.

Visual Search Strategies of Tag Clouds - Results from an Eyetracking Study

Tag clouds have become a frequently used interaction technique in the web in the past couple of years. Research has shown the influence of variables such as tag size and location on the perception of tag clouds. However, several questions remain unclear. First, little is know on how tag clouds are perceived visually and which search strategies users apply when looking for tags in a tag cloud. Second, there are variables, especially tag location, were prior work comes to conflicting results. Third, several approaches to present tag clouds with the tags semantically clustered have been proposed recently. However, it remains unclear which effects these new approaches have on the perception of tag clouds. In this paper we report the results of an extensive study on the perception of tag clouds using eye tracking technology that allows answering these questions.

Exploring Persuasion in the Home: Results of a Long-Term Study on Energy Consumption Behavior

This paper presents a seven-months field study on a persuasive ambient display in private households. The FORE-Watch aims at adjusting the consumption behavior of energy users in 24 multi-person households and persuading them to change their timing of consumption activities; half of them were shown a forecast of the occupancy rate of the local energy grid (i.e., grid status), and the other half were shown how much energy will be delivered by green sources such as windmills (i.e., green energy). Our qualitative and quantitative survey and the energy consumption data revealed that the grid status group showed a more constant behavior than the green energy, indicating that the more dynamic forecast presentation did not lead to the same type of behavior change as the static forecast presentation. Overall, the FORE-Watch aroused awareness, attention and interest through permanent presence, clear and simple information, and changed the energy consumption behavior of our participants.

Comparing different layouts of tag clouds: Findings on visual perception

With the emergence of social tagging systems and the possibility for users to extensively annotate web resources and any content enormous amounts of unordered information and user generated metadata circulate the Web. Accordingly a viable visualisation form needs to integrate this unclassified content into meaningful visual representations. We argue that tag clouds can make the grade. We assume that the application of clustering techniques for arranging tags can be a useful method to generate meaningful units within a tag cloud. We think that clustered tag clouds can potentially help to enhance user performance. In this paper we present a description of tag clouds including a theoretical discourse on the strengths and weaknesses of using them in common Web-based contexts. Further recent methods of semantic clustering for visualizing tag clouds are reviewed. Findings from user studies that investigated the visual perception of differently arranged depictions of tags follow. The main objective consists in the exploration of characteristical aspects in perceptual phenomenons and cognitive processes during the interaction with a tag cloud. This clears the way for useful implications on the constitution and design factors of that visualisation form. Finally a new approach is proposed in order to further develop on this concept.