Problem Definition
Current interaction techniques with hand held devices are marginal at best. They utilize an interface that was developed for traditional computing; utilizing the keyboard, mouse and a large display as a means for user interaction.
As such, current interface design for such devices do not compliment the
medium in which it was meant to be interacted with, resulting in a system that is not ideal for the user.
As such, current interface design for such devices do not compliment the medium in which it was meant to be interacted with, resulting in a system that is not ideal for the user.
The Design
Pressurized Hierarchical Pie Menu (PHPM) is a generic hierarchic menu system that is designed to work within the confines of a limited screen area, while taking advantage of the natural affordance of the stylus pen for input interaction.
The System utilizes:
- Pie Menu - Allows for all menu elements to be equally distanced from the center of the circle. The user can thus make equal distanced strokes with the stylus to access them.
- Pen Pressure - Applying pressure to the screen from the stylus, causes "altitudinal" effects to be applied to the pie menu. Such altitudinal effects try to simulate a sense of going further down within the screen and thus, into another deeper layer of the pie menu. This gives the user a greater variety of menu elements without ever having to traverse the X and Y axis; minimizing the need for screen space.
- Hierarchy - A menu that includes a menu item from which a submenu descends.
Click Here for an example
Note: Different colours signify different altitudinal levels, and hence different content in the pie menu.
The System utilizes:
- Pie Menu - Allows for all menu elements to be equally distanced from the center of the circle. The user can thus make equal distanced strokes with the stylus to access them.
- Pen Pressure - Applying pressure to the screen from the stylus, causes "altitudinal" effects to be applied to the pie menu. Such altitudinal effects try to simulate a sense of going further down within the screen and thus, into another deeper layer of the pie menu. This gives the user a greater variety of menu elements without ever having to traverse the X and Y axis; minimizing the need for screen space.
- Hierarchy - A menu that includes a menu item from which a submenu descends.
Click Here for an example
Note: Different colours signify different altitudinal levels, and hence different content in the pie menu.
The Experiment
In order to determine the validity of the Pressurized Hierarchical Pie Menu an experiment was carried out, whereby the user had to navigate to a specific element of the menu given the exact graphical representation of the path to take [Expert Behaviour]. The purpose of the experiment was to determine the participant's Error Rate, and Time of Completion, over multiple blocks to see if a learning effect had taken place.
The Experiment consisted of two users, both of which did 3 blocks of 108 trials (all possible permutations) in a random order.
Independent Variables:
- Pie Menus had 4 Pie Slices
- Pie Menus had 3 Altitude Levels
- Pie Menus had 1 Depth Level (Hierarchy)
The Experiment consisted of two users, both of which did 3 blocks of 108 trials (all possible permutations) in a random order.
Independent Variables:
- Pie Menus had 4 Pie Slices
- Pie Menus had 3 Altitude Levels
- Pie Menus had 1 Depth Level (Hierarchy)
Aggregate Results
Time of Completion in Milliseconds
Error rate in percentage
Error rate in percentage without outliers
Individual Trial Results
Conclusions
- The preliminary data gathered from the experiment indicates that as the user gains experience with the system, he/she is better able to interact with it; gaining a quicker time for completion, as well as general trend towards a decreasing error rate. However, the scope of the experiment was rather limited making it insufficient to make any strong inferences or evaluation. The data does show some initial promise but further more rigorous experimentation will be required, particularly with increasing the hierarchical and altitudinal levels.
References
- The Limits of Expert Performance Using Hierarchic Marking Menus. Gordon Kurtenbach, William Buxton. May 1993. Proceedings of the SIGCHI conference on Human factors in computing systems.
- An Empirical Comparison of Pie vs. Linear Menus. J. Callahan, D. Hopkins, M. Weiser, B. Shneiderman. May 1988. Proceedings of the SIGCHI conference on Human factors in computing systems.
- User Learning and Performance with Marking Menus. Gordon Kurtenbach, William Buxton. April 1994. Proceedings of the SIGCHI conference on Human factors in computing systems: celebrating interdependence.
- Some Design Refinements and Principles on the Appearance and Behavior of Marking Menus. Mark A. Tapia, Gordon Kurtenbach. December 1995. Proceedings of the 8th annual ACM symposium on User interface and software technology.
- Fluid Interaction Techniques for the Control and Annotation of Digital Video. Gonzalo Ramos, Ravin Balakrishnan. November 2003. Proceedings of the 16th annual ACM symposium on User interface software and technology.
- Pressure Widgets. Gonzalo Ramos, Matthew Boulos, Ravin Balakrishnan. April 2004. Proceedings of the 2004 conference on Human factors in computing systems.
Contact Info
- Email: christian.pironchen at utoronto.ca