Wiebke Köhlmann

What You Feel Is What You Get: Mapping GUIs on Planar Tactile Displays

Exploiting the advantages of planar tactile displays, we aim for efficient and effective information retrieval for blind users. To facilitate orientation, we define four regions segmenting the available space: header, body, structure, and detail region. Furthermore, we suggest four views--layout, outline, symbol and operating view--that define how detailed and in which manner information from window-based applications is displayed on tactile displays.

Tactile Paper Prototyping with Blind Subjects

With tactile paper prototyping user interfaces can be evaluated with blind users in an early design stage. First, we describe two existing paper prototyping methods, visual and haptic paper prototyping, and indicate their limitations for blind users. Subsequently, we present our experiences while preparing, conducting and analysing tests performed using tactile paper prototyping. Based on our experiences, we provide recommendations for this new usability evaluation method.

Communicating through gestures without visual feedback

Human-machine interaction by gestures helps to improve communication: it utilizes means of communication which are common to humans but alien to machines. We consider ergonomic, functional and semantic issues in gesture-based interfaces without visual feedback. Such situations arise with the unobtrusive usage of wearable devices but, more importantly, with interfaces for visually impaired persons. We consider the latter scenario -- that of blind users -- in view of forthcoming haptic interface technology and investigate properties of gestural interaction models.

Alternative Concepts for Accessible Virtual Classrooms for Blind Users

The use of virtual classrooms by blind users is hindered e.g. By inaccessible user interfaces, graphical and dynamical content, as well as synchronous communication. Based on a requirements catalogue for accessible virtual classrooms and existing concepts to eliminate barriers for blind learners, alternative concepts are presented for a two-dimensional Braille display. An evaluation using tactile paper prototyping indicates an improvement towards accessibility and equal usage for all participants.

FreshUP — Implementation and evaluation of a pervasive game for freshmen

Students beginning their studies at university face manifold problems such as orientation in a new environment and organizing their courses. In contrast to a conventional scavenger hunt, mobile pervasive games, bridging in-game and real world activities, have the potential to provide help in a motivating manner using new technology which is currently becoming more and more common. This paper presents the implementation and evaluation of the pervasive browser-based learning game “FreshUP”, which aims at helping to overcome the initial difficulties of freshmen.

Identifying barriers to collaborative learning for the blind

Digital materials can help blind and visually impaired students to participate in e-learning and collaborative settings. The use of multimedia content enhances the learning experience of sighted students, but new barriers arise for the visually impaired. This paper describes surveys on e-learning and collaborative settings, defines existing barriers and presents a survey on the use of computer usage, e-learning and collaborative learning amongst 42 blind and visually impaired users in educational and professional life.

User-interface filter for two-dimensional haptic interaction

General principles for the design of user interfaces for systems software are discussed, which take into account the constraints imposed by special user groups like visually impaired or blind persons and by special displays like haptic displays or very small screens.

Touching graphical applications: bimanual tactile interaction on the HyperBraille pin-matrix display

Novel two-dimensional tactile displays enable blind users to not only get access to the textual but also to the graphical content of a graphical user interface. Due to the higher amount of information that can be presented in parallel, orientation and exploration can be more complex. In this paper we present the HyperBraille system, which consists of a pin-matrix device as well as a graphical screen reader providing the user with appropriate presentation and interaction possibilities. To allow for a detailed analysis of bimanual interaction strategies on a pin-matrix device, we conducted two user studies with a total of 12 blind people. The task was to fill in .pdf forms on the pin-matrix device by using different input methods, namely gestures, built-in hardware buttons as well as a conventional PC keyboard. The forms were presented in a semigraphic view type that not only contains Braille but also tactile widgets in a spatial arrangement. While completion time and error rate partly depended on the chosen input method, the usage of special reading strategies seemed to be independent of it. A direct comparison of the system and a conventional assistive technology (screen reader with single-line Braille device) showed that interaction on the pin-matrix device can be very efficient if the user is trained. The two-dimensional output can improve access to .pdf forms with insufficient accessibility as the mapping of input controls and the corresponding labels can be supported by a spatial presentation.

Non-visual Usage of Virtual Classrooms: An Analysis Using Screen Reading Software

Inclusion gains in importance in educational settings and thus also in synchronous online learning and collaboration. New barriers arise for blind users because of dynamic, synchronous and graphical content and interfaces. This paper defines scenarios, analyses to what extent these virtual classrooms can be used by blind learners using the screen reading software Jaws and describes barriers encountered.