ÍNDICE DE CRECIMIENTO.

Our user study is an introductory exploration to understanding how DH pairs communicate when collaborating remotely using a computer system to mediate the communication. Therefore we evaluate the collaborators experience in a variety of situations, which results in a factorial user study design. In summary, collaborators complete the task of playing checkers against the computer or creating a brainstorm diagram. We compare the experience of two hearing collaborators (who we refer to as a HH pair) to that of a deaf person and a hearing person collaborating (who we refer to as a DH pair). Participants use separate computers with a shared workspace and tools for communicating with three configurations, including video conferencing, a telepointer for pointing and gesturing at the workspace, and chat messaging. We make a within subjects comparison of the collaborators experience using the three configurations.

5.1.1 Independent variables

Figure 5-1 shows the three interface conditions we evaluate in the user study. The conditions are explained in more detail below.

Deaf/Hearing DH pair Hearing/Hearing HH pair Checkers Brainstorm Diagram Facetop Conv. video conf.

Facetop with Telepointer Medium of Conversing Task Video configuration

Video conferencing and telepointer configuration

In the study there are three video conferencing configurations in conjunction with a telepointer, with which participants point and gesture at a shared workspace. In all cases, the video is high resolution and with minimal latency so that the video is detailed and responsive allowing participants to easily recognize the other participant's gestures. The first configuration is a conventional video conferencing setup. As shown in Figure 5-2 (a), one participant's screen shows a 3-by-4 inch video of each collaborator. A participant sees himself to verify the camera is setup properly. The video is on the same screen next to the shared workspace application. This video conferencing configuration is always used with a telepointer.

a) b)

Figure 5-2. a) Conventional video conferencing configuration b) Facetop video configuration

The second video conferencing configuration is the Facetop (Stotts, Smith et al. 2004) setup, shown in Figure 5-2 (b) In Facetop, video of participants is transparently overlaid on the entire desktop. Participants can easily distinguish the participants' video from the shared workspace. Through the Facetop video (unlike the conventional video), participants can gesture and point at the shared workspace similar to how they would when face-to-face. A participant sees his own video for simple self registration of the camera and to identify where his finger gesture points. The latency of the video is low enough for a participant to easily gesture at the workspace. This is important because a

significant lag in the video would cause a participant to readjust as the video catches up with the participant's motion.

In one study situation participants use the Facetop video with a telepointer and in another study condition participants use the Facetop video without a telepointer. Without the telepointer, participants point with their fingers at the workspace through the overlaid video, similar to being face-to-face. With the telepointer, participants have a choice between pointing with the telepointer or through the video.

Checkers and diagram tasks

In the user study pairs of participants complete one of two tasks. One task is playing checkers against the computer. The other task is completing a brainstorming diagram. The tasks encourage collaboration because completing the tasks requires the participants to exchange ideas and make decisions. We chose the tasks to represent different kinds of interaction.

In the checkers task, a pair of participants play checkers against the opponent controlled by the computer. On each turn, the pair decides their checkers move. The pair must evaluate their pieces and the opponent's (computer's) pieces. Participants mainly exchange ideas pointing at the checkers board. Conversing is helpful but not necessary. The pointing interaction limits the ideas participants' can express and does not reflect a more general collaboration.

In the diagram task a pair of participants group words into categories. At the start, participants are given a topic (hobbies, family, food) and given a moment for each to independently brainstorm five words. Then the participants share their words and decide how to group the words into categories. The visual diagram the pair creates is a tree structure with the main topic as the root node. The initial words might be categories in the tree or leaf items.

Unlike the checkers task, the diagram task represents a more realistic

collaborative task. The negotiation is an open ended creative process. Participants have to converse in order to group words into categories. Participants have the flexibility to choose how to communicate; such as editing the shared whiteboard or by exchanging chat messages.

The checkers task is more suitable than the diagram task for conducting a

controlled experiment. By making checkers moves, participants are rapidly repeating the interaction of deciding on a move. We have instrumented the checkers application to gather low level information about participants' checkers moves and mouse activity.

5.1.2 Measurements

In the user study we make the following measurements:

1. Questionnaire and interview participants: Gather the perspectives and experiences of the participants completing the user study. Although the data is subjective, the participants’ perspective is the most significant because people similar to them will ultimately use the interfaces. 2. Video, Audio, chat recording of sessions: Used to make observations

about the collaborators’ interaction. The interactions will be coded and tallied.

3. Logging events in shared application: The monitored activities can be tallied as another metric to categorize the interaction. Analyzing these low level measurements has to be done with care as there might be several possible explanations for a given result.

5.1.3 Participants

The study involved 26 participants – six HH pairs and seven DH pairs. Seven participants (in each of the seven DH pairs) are deaf or hard of hearing and do not understand spoken language. The hearing participants in the DH pairs are familiar with the deaf community and have some understanding of the situation of the deaf participant. Hearing participants who know ASL were asked to refrain from using it in order to simulate the scenario we are evaluating.

For this study the experimenter did not know ASL to communicate with the deaf participants, however, we prepared two videos to convey the informed consent

participants completed and instructions of the tasks. One video is a closed captioned Quicktime video created with the Magpie closed captioning project. The second video is an ASL video we created. The video included a screen capture of Facetop when

explaining the shared workspace applications. Using Facetop, it was beneficial that the ASL interpreter could sign and point at the application. The remaining discussions between the deaf participant and the experimenter were mediated by someone who could sign or simply writing written or chat messages.

5.1.4 Computer setup

Two participants complete a user study session. Figure 5-3 shows the setup of the user study.

Computer screen

Participant 1

Screen creates a solid Background For the video

captured by the Facetop cameras

Computer screen

Facetop Camera

Network connection Facetop video

Video

viewer

Record audio/video user study session

Participant 2

Monitor

Figure 5-3. Facetop user study setup of workspace with two participants and user study experimenter.

The room is set up to simulate the participants being remote. There is a divider between them so that they cannot turn to each other as in face-to-face communication. Being in the same room the audio quality is ideal for a HH pair; unlike when the audio is transmitted and the signal is delayed or distorted. The participants still wear a headset with microphone. Nothing is heard in the headset but the microphone is used to capture the audio recorded on the video tape of the session.

Also there is a white screen background behind the participants. The background helps make the video image of the collaborator easier to view and understand. Without the background the video would be cluttered with an image of the room. The screen also happens to separate the user study experimenter from the participants; the participants will be less aware of and less influenced by the experimenter’s presence. The

experimenter observes the live video image on a video display connected to the camera recording the session.