Paper Reading #18: Speeding pointing in tiled widgets: understanding the effects of target expansion and misprediction

Comments
Shena Hoffman
Evin Schuchardt

Reference Information

Title: Speeding pointing in tiled widgets: understanding the effects of target expansion and misprediction

Authors:  Jaime Ruiz  University of Waterloo, Waterloo, ON, Canada 
               Edward Lank  University of Waterloo, Waterloo, ON, Canada 

        

Presentation Venue: IUI '10 Proceedings of the 15th international conference on Intelligent user interfaces ;
ACM

New York, NY, USA ©2010

Summary

In this paper, the authors discuss a pointing facilitation technique, in addition to their desire to improve the time it takes a user to reach his/her pointing target when using a graphic interface. In particular, they wish to remedy tiled-like target arrangements via widget target expansion. We can give the example of the font and point size selection widgets, common in word processing programs like Microsoft Word.  A common problem that researchers face is the limited amount of screen space around tiled targets. Expansion of a target results in less available surface, and affects neighboring targets. Occlusion and displacement, the authors say, are two problems that can occur when a target is expanded. In this paper, the researchers have relied on previous work for single target expansion, to guide their design. The technique the authors have focused on is a technique for predicting where a user will select in real time. It is called kinematic endpoint prediction (KEP). The way it works is that it “uses the motion profile of a user to define a region of interest on the display.”

The researchers have performed two experiments to test the possibility of using KEP for multiple selected target expansion. In their first experiment, they tested to see expanding a certain set of targets'. In addition target displacement was assessed. Target displacement is the result of targets near the expanded targets shifting their positions to make room for the expanded target. They presented users with a random set of pointing tasks with some tasks using expansion with a simulated predictor said to be highly accurate and some using no expansion. There were seven possible tiles to select.

In the second experiment they used a similar setup, however in this case, the aim was to use the KEP algorithm to predict which targets should be expanded. The target arrangement used on the screen was different because the entire computer screen was filled with targets rather than just displaying seven targets.

Some of the findings of the two experiments were that:

• Target expansion does improve pointing and selecting performance, but better when there is a small set of targets.
• A minimum requirement for a target technique to be useful is an accuracy greater than 56.5 percent.
• There is a limit to how much a target can shift when expanded. As Fitt's Law explains, increase in distance reduces the likelihood of a user pinpointing his/her desired target.

DiscussionI liked this paper. The authors are trying to improve graphic interfaces by diminishing the time it takes a user to select their desired target. Current programs such as Microsoft Word that use the Ribbon style display, have organized targets in an intuitive way, however the sheer amount of widgets, and options eventually gets tiresome, especially when you are looking for a new widget. The authors' experiments were thoroughly explained, and the data they gathered was well analyzed. The technique the authors are trying to improve is very important as this is a very common task performed by users of graphic interfaces; therefore improving pointing performance by even a small margin can greatly improve a user’s productivity with graphical user interfaces.