This paper pointed out a very good point: to interact with a board via touch, one need to stay within arm reach, but within that distance, the viewable area is limited. Therefore, there exist a maximum screen size for interactive whiteboard that one can comfortably use. If the display is used as a presentation tool for the user, the limitation is ok because presenter knows what is on the screen, therefore having limited viewable area is more tolerable. However, if the display is for performing tasks such as the route planning example, then having a sense of a larger picture is desirable. I wonder how to design a system can allow performing both tasks? Would having a display to switch between the two modes depending on the number of users detected is a good idea?
"Simulates input was accomplished without explicit discussion". The paper think this is due to the board only supports one touch, but I wonder if this is always how we communicate? Two people can't talk to each other at the same time. Therefore, supporting more than two touches in this case shouldn't change the fact that people are taking turns.
The paper pointed out the people have strong preference to work close together because of ease of communication and shared visuals. I wonder if this is because two participants are performing the task, not more. I think it would be interesting to see how well the proximity works with more than two participants because when two people are at the display, they have a view of each other's face when talking to each other. When having a third participant, there will exist a person that might block the view. This extra person will make the side-side communication not as enjoyable. I wonder if this will have a preference impact on the participants.
Another interesting point is the different amount of annotation created by the users from different settings. People use more annotation when they are far apart from each other. I think this is a reflection that people need to visually emphasize their intention because people are far away.
