004 - Visual Simliarity of Pen Gestures

Summary:

This paper seems to be the premise behind creating Quill as in the aforementioned Long paper. It explains why all the research was done, mainly sticking to the similarities of some gestures that humans may not be able to distinguish. It acts as an overview of all the research done that led to the Quill program. It starts with the examining of different interfaces to design with, different formulas and psychology examples of similarity, and the number of dimensions of a Multi-Dimensional-Scaling technique to use. It then lists the different experiment trials run and what each outcome was. The first trial tested the different features to see which ones were best predictors of similarity of gestures, which turned out to be most of the 11 listed features of Rubine (minus bounding box and total length) and several features that Long et al designed (I think, I could be wrong), and what dimensions they were in. The next trial was over a specified set of gestures to see how people would perceive them (absolute angle and aspect, length and area, and rotation-related features). Trial 1 ended in a seemingly unexplained split in the group, but adding the gesture "sets" in Trial 2 brought the group together more.

Discussion:

I gotta say that Long's results didn't SOUND promising. Even with decent results, I dislike the idea of splitting the users into groups in trial 1, and trial 2 said that even without the outliers the overall usage didn't improve. I applaud Long at trying to REMOVE features, because if you had a program with a million features it would be able to tell exactly how different every gesture was, but no one would want to use it. I do question why they took out the features in Rubine that dealt with time and pretty much removed it from the equation. I can only guess that they wanted to remove the "I draw faster than him" part of similarity, since a circle drawn in a second can look the same as one drawn in a minute, though I think it could still be useful in some cases.