Director Rick Omanson’s co-authored manuscript entitled "Categorization Costs for Hierarchical Keyboard Commands" will be presented on May 11 at the CHI Conference on Human Factors in Computing Systems, in Vancouver, BC, Canada. Omanson, along with Craig Miller and Svetlin Denkov, both of DePaul University, investigated the cost of categorical decision with user practice. Knowing keyboard use is proven faster than mouse use, due to less movement, and that toolbars are faster than menus, Omanson, Miller and Svetlin’s analysis suggests that even with extensive practice, users do not skip the menu category decision of deciding which menu contains the item. Because menu use always seem to involve a category decision, the speed advantage of using a keyboard to issue commands from menus rather than using a mouse to issue commands from a toolbar becomes apparent to users only after extensive practice.
Previous research comparing methods of issuing commands found that selecting a toolbar item is faster than selecting an item from two menus with either a mouse or keyboard shortcut. Over the course of 90 trials, however, the keyboard method showed the most improvement, nearing the toolbar response time. The study presented in this paper compared the response time of the keyboard method across 240 trials when items were drawn from a single versus two menus. Throughout the trials, the 1-menu condition produced selection times that were on average 600 ms to 800 ms faster than the 2-menu condition suggesting users in the 2-menu condition were not able to bypass the menu decision by chunking the 3-key sequence into one cognitive unit. Models are presented to describe performance at various stages of learning. Practical implications are that hierarchical, category based keyboard commands do not provide a clear advantage to toolbar-based selection and that theory-based evaluation methods may need to reflect this result.
Originally a small conference for psychologists interested in user interface design, the annual CHI conference has grown to include a very diverse participant group (such as interaction designers, computer scientists, engineering psychologists, developers, performing artists, and more), and to deal with larger problems such as the organizational integration of technology. This year’s conference marks 29 years of research, innovation and development in the field of Human-Computer Interaction and is expected to draw more than 2500 professionals from over 40 countries. CHI 2011 offers provocative opportunities for connecting and interacting with future technologies. Visit http://chi2011.org for more information on this