Two-handed input

Comments on Two-handed Input in a Compound Task, by Paul Kabbash, William Buxton, and Abigail Sellen, In Proceedings of CHI '94: Human Factors in Computing Systems, Boston, MA, March 1994, pp. 417-423. [PDF] (Note that the HTML has no figures)
  1. I really like the idea of two-handed input, although it does seem to be focussed mainly on drawing and similar activities. I have been trying to think of other activities that require both hands but do not fit Guiard's three criteria -- so far, the only one that comes to mind is the use of the right hand to navigate rapidly and the left to mark or to "mind place," as when rapidly flipping through a book. (Navigating the Web comes to mind.) Other assymetric activities, like driving, playing the cello, and gesticulating wildly, aren't computer-amenable. Although, come to think of it, two-handed input has been used in various ways in computer music for ages.
  2. The toolglass has two features which separate it from the other techniques: transparency, and click-through. Transparency alone might improve the Palette.
  3. I would like to know how the actual physical positioning of the hands affects performance. In these experiments, the menu and cursor position are controlled simply by moving some relative distance; if positioning instead reflected physical positioning such that the hands were close together when the menu and cursor coincided, the results might be different.
  4. My personal preference for an HCI goal would be not "to accelerate the process whereby novices perform like experts," but "to enable experts to perform like experts."

Comments on The Design of a GUI Paradigm Based on Tablets, Two-hands, and Transparency, by Gordon Kurtenbach, George Fitzmaurice, Thomas Baudel, and Bill Buxton, In Proceedings of CHI '97: Human Factors in Computing Systems, Atlanta, GA, March 1997, pp. 35-42.

  1. Despite the inherent bias, "left" and "right" would have been a lot easier to read than "ND" and "D."
  2. I really like the absence of "screenjunk" in this interface.
  3. Interesting that the toolglass didn't make it into the product. Without having used a toolglass, I have to wonder how "natural" it feels, as there's no obvious analogy with conventional (physical) tools.
  4. While watching the video on Wednesday, I was struck by the abruptness with which the toolglass appeared and disappeared compare with the animation and dissolving of Tuesday's SIMS247 presentation.

John Reekie, March 20th, 1998.