Research on blind-sighted collaborators

We are aware of only one research project that explores computer interfaces to support collaboration of a blind-sighted pair. We review the project, which demonstrates the feasibly of such a collaboration. We also describe how our research expands

knowledge in this area.

3.1.1 Previous research

Winberg's research (Winberg and Bowers 2004) introduced the CSCW

He demonstrates that it is possible for the pair to share a workspace and constructively complete a task. The user study task is to complete the Tower of Hanoi game (discs of different sizes are moved between three poles, according to constraints). The shared workspace is the game board. Each collaborator uses the most appropriate display: the sighted person uses a visual display and the blind person uses an audio display.

Winberg also developed the audio display for this project. The audio display is based on direct manipulation, which is how most common graphical user interfaces (GUI) work. In direct manipulation users can manipulate objects – represented visually in a GUI; for example, in the Tower of Hanoi game a user can click and drag the disc from one pole to another. Winberg's audio interface functions similarly. Instead of a visual representation, objects appear to emit sounds; for example, in Tower of Hanoi each disk and each pole has a unique sound. The disks and poles have the same spatial layout, as in the visual display. A blind person uses a mouse to explore the shared workspace

displayed auditorily. As the mouse moves the person hears the objects close to the mouse position. Objects are manipulated like in the visual display; for instance, by listening for the objects, a user can select a disc and can drag a disc from one pole to another.

In the evaluation, a blind/sighted pair collaborated to solve the Tower of Hanoi game. Three pairs participated in the study. Each pair used one computer with a visual display (monitor) and an auditory display (headphones). The collaborators shared a telepointer that they had to coordinate in controlling. In theory, when the sighted person controlled the telepointer, the blind person could hear the objects it was passing over.

Overall, the collaborating pairs were able to successfully communicate and

complete the task. The pairs’ work was balanced, such that, after discussing the move, the blind person and the sighted person would take turns to interact with the interface and complete the move. Although the participants took turns to control the interface, sometimes the blind person would start to control the telepointer before the sighted person was done. The problem was quickly rectified: listening to the audio display, the blind person understood the problem and let the sighted person finish.

Occasionally, it would be complicated for the blind person when the sighted person made a series of changes to the game. When the blind person took control again, he/she would scan the entire game board to clarify the state of the game. The researchers’

observation is that the blind person integrates many sources of information, including listening/interacting with the audio display, talking with the sighted collaborator, and memory. Also, there is a delicate balance with a blind person listening to both the audio interface and the sighted collaborator. The researchers’ suggestion for future work is to design interfaces such that they provide the functionality to assist the collaborators in the observed situations.

3.1.2 Our contributions

Our research in collaborative interfaces for a blind/sighted collaborating pair builds on the experience from the Tower of Hanoi interface. Like in the Tower of Hanoi interface, a sighted person uses a visual interface and a blind person uses an audio interface. The interfaces, however, are loosely coupled so that each person can navigate the application independently. Also, the interfaces are laid out differently to most appropriately accommodate how a user accesses the interface. The semantic pointing mechanism in our interface lets the collaborators shift focus to the same object. With this interface, the confusion observed in the Tower of Hanoi game should be minimized. Also our collaborative task of viewing and editing diagrams further demonstrates the range of collaborative applications a blind/sighted pair can participate in. Diagrams demonstrate a more complex, shared workspace, including detailed textual information that the

collaborators will be able to work with.

The loosely coupled collaborative interface used in this research is based on CSCW research in flexibly coupled interfaces. Suite (Dewan and Choudhard 1991) and Rendezvous (Patterson, Hill et al. 1990) are two research projects that demonstrate this research. The original purpose was to accommodate flexibility in which collaborators work. Before flexibly coupled interfaces, collaborators’ interfaces were identical, and they had to work on the same task. However, collaborators, such as coders or prose editors, would sometimes prefer to divide the task and work on separate parts. Furthermore, instead of sharing every edit, a person may want to make several edits before sharing with the collaborator.

The flexibility of the interfaces is based on the coupling values of the shared model (i.e. data) and display. Consider a card game where the players are remote and use

separate computers. In this case the coupled display shows the card table and the player's hand of cards. The table would be rotated appropriately for each player so that the table appears in front of the player. Also a player only sees his own hand of cards, because it is private information. When cards are played, they appear publicly on the table for everyone to see.

To illustrate coupling values in the shared model, consider the card game, where two people play together and share a hand of cards (maybe an expert is teaching a novice). The coupled value to consider is the card to be played. The team of players would want to show each other which card to play. When they have decided on a card, they can make the value public, i.e., place the card on the table. So the played card value would be private to the team before it is made public. This is an example of flexible coupling.

Pointing in flexibly coupled interfaces is done using a semantic pointer. When one user selects an object to be pointed at, the corresponding object in the other user’s interface is highlighted.

In our collaborative diagram interface for the blind/sighted pair of collaborators, the display is flexibly coupled and the values in the shared model are tightly coupled. A sighted person uses a typical visual interface, whereby the blind person interactively navigates a diagram and listens to textual descriptions. At least in the initial research, we assume collaborators see identical models of the diagram, and therefore the values of the model are tightly coupled.