Michaela Kauer

User study of the improved Helios voting system interfaces

There is increasing interest in cryptographic verifiability in remote electronic voting schemes. Helios is one example of an open-source implementation. In previous work, we proposed an improved version of the original Helios interface in version 3.1 for vote casting and individual verifiability. We now test this interface in a mock mayoral election set up with 34 users. Users are given instructions and fill out questionnaires before and after the vote casting process. Data on mouse movements and time is collected and a modified helmet with eye tracking lenses is used to capture eye movement data. The study shows that the interface is easy to use while people have difficulty understanding the motivation for and the concept of verifiability.

How to conduct a car? A design example for maneuver based driver-vehicle interaction

Conduct-by-Wire is a vehicle guidance paradigm, which investigates the possibility of controlling an automobile by maneuver commands. The focus of this paper is to show one possible interaction strategy for maneuver-based vehicle guidance between driver and vehicle by means of discrete maneuvers. Therefore, the paper starts with a short introduction to the advantages of maneuver-based vehicle guidance and proceeds to the current design option for maneuver-based driver-vehicle interaction chosen by the TU Darmstadt. This includes the presentation of the user interface as well as the basic assumptions for maneuver-based interaction. This paper is finished by a specific example for the maneuver “Lane Change right”, which includes system behavior, as well as, information displaying and some restricting facts which are presented together with possible countermeasures.

Development of a cooperative system behavior for a highly automated vehicle guidance concept based on the Conduct-by-Wire principle

Conduct-by-Wire (CbW) is a research project which breaks away from todays vehicle guidance by shifting the vehicle control task from a stabilization level to a conducting level. Instead of continuous stabilization on a designated trajectory - using the conventional control elements for manual steering, braking and accelerating - a Conduct-by-Wire vehicle is controlled by means of maneuver commands. By keeping the driver in the loop, the vehicle guidance is cooperatively shared between the driver and the automation. This article introduces an approach for the analysis of realizable automation levels and the design of a cooperative system behavior depending on the interaction concept between the human driver and the automation. Following a top-down approach, different driving scenarios are systematically analyzed as to the information needs that occur. This approach builds the basis for assessing the technical feasibility of a maneuver-based vehicle guidance concept based on the Conduct-by-Wire principle.

Share with strangers: Privacy bubbles as user-centered privacy control for mobile content sharing applications

A continually increasing number of pictures and videos is shared in online social networks. Current sharing platforms, however, only offer limited options to define who has access to the content. Users may either share it with individuals or groups from their social graph, or make it available to the general public. Sharing content with users to which no social ties exist, even if they were physically close to the places where content was created and witnessed the same event, is however not supported by most existing platforms. We thus propose a novel approach to share content with such users based on so-called privacy bubbles. Privacy bubbles metaphorically represent the private sphere of the users and automatically confine the access to the content generated by the bubble creator to people within the bubble. Bubbles extend in both time and space, centered around the collection time and place, and their size can be adapted to the users preferences. We confirm the user acceptance of our concept through a questionnaire-based study with 175 participants, and a prototype implementation shows the technical feasibility of our scheme.

Verification of a maneuver catalog for a maneuver-based vehicle guidance system

A quickly increasing number of advanced driver assistance systems are implemented in modern vehicles. Already today, this can lead to a mental overload of drivers, since every single system has its own control elements. In the future, innovative vehicle interaction concepts, with a global design philosophy, will be necessary. Conduct-by-Wire (CbW) is an approach to relieve drivers from stabilization tasks, as the vehicle will be controlled by assigning concrete elements, the maneuvers, which are executed automatically. This could possibly lead to a more cognitive way of driving, keeping the driver closer in the loop. The basic requirement for this concept is the development of a maneuver catalog from the drivers point of view, in order to enable easy, even intuitive driving. Therefore, this paper describes how a driver would divide a specific track into single maneuvers, based upon an already existing catalog of commands. An innovative experimental concept is developed, consisting of a field and laboratory study, using the ‘thinking aloud’ method, an eye tracking and a decision point analysis.

Improving privacy settings for facebook by using interpersonal distance as criterion

The possibility to define custom privacy settings in Facebook has been improved over the last years. Still, numerous users do not know how to change those settings or do not use the settings because they are cumbersome to use. Within this paper a new method for defining the privacy settings in online social networks is presented that uses the social distance between users as setting criterion. This approach was tested as a paper prototype in a first user study with 10 participants. Results show that the number of errors was significantly decreased and that the subjective evaluation of the interface was promising.

Adopting the CMU/APWG Anti-phishing Landing Page Idea for Germany

Phishing attacks still pose a significant problem and purely technical solutions cannot solve this problem. While research literature in general shows that educating users in security is hard, the Anti-Phishing Landing Page proposed by CMU researchers seems promising as it appears in the most teachable moment -- namely once someone clicked on a link and was very likely to fall for phishing. While this page is already in use and exists in many languages we show that it is not effective in Germany as most users leave the page immediately without having read any advice. We therefore explore options to adopt their ideas for Germany. We focus on which are the trustworthy institutes that could provide such a landing page on their web pages and what is an appropriate headline and design.

User acceptance of cooperative maneuver- based driving - a summary of three studies

Modern cars offer drivers support with the help of a number of driver assistance systems. Those systems aim to relieve drivers through assumption of sub parts of the driving task (e.g. in case of an Adaptive Cruise Control by regulation of vehicle speed and time gap to preceding vehicle). Today, systems are controlled and monitored separately which leads to efforts to combine the functionality of all systems in an overlying assistance for drivers. The approach of the University of Technology Darmstadt is called Conduct-by-Wire and can be seen as a cooperative maneuver-based driving paradigm, where the driver gives maneuver command to the systems which are automatically executed. This paper summarizes the results of three studies which investigated the user acceptance of this driving paradigm. Overall, it can be said that the acceptance of the system depends on personal traits of the driver and on the driving situation. Almost all participants are willing to use Conduct-by- Wire for routine tasks such as commuting, which makes the systems interesting for company cars. Still, there remain a number of drivers who are not willing to use such a highly automated system at all.

A Comparison of American and German Folk Models of Home Computer Security

Although many security solutions exist, home computer systems are vulnerable against different type of attacks. The main reason is that users are either not motivated to use these solutions or not able to correctly use them. In order to make security software more usable and hence computers more secure, we re-ran the study by Wash about “Folk Models of Home Computer Security” in Germany. We classified the different mental models in eleven folk models. Eight of the identified folk models are similar to the models Wash presented. We describe each folk model and illustrate how users think about computer security.

Temporal analysis of the gate concept as enabler for highly automated driving based on the Conduct-by-Wire approach

Conduct-by-Wire (CbW) is an innovative vehicle guidance concept that shifts the vehicle control task from the stabilization level to the guidance level. Instead of continuous stabilization on a designated trajectory - using the conventional control elements for manual steering, braking and accelerating - a CbW vehicle is controlled by means of maneuver commands. One important element on the way to realizing CbW might be the gate concept that consists in a segmentation of the vehicle guidance task and the identification of decision points during the execution of a drivers maneuver command. This article introduces an approach for the analysis of the time available for decision-making in systematically derived scenarios. For the first time, the results offer the basis for a suitability evaluation of the gate concept and thus a fundamental contribution to the technical feasibility assessment of CbW.