Meeting Leader:
Whitney Quesenbery
Whitney Quesenbery leads the design group at Cognetics Corporation, an interactive design company dedicated to the creation of user-centered, LUCID software. Her email address is whitneyq@cognetics.com.
written by Anne Marie Jackson
Originally published in News & Views November 1998 issue. Copyright 1998 STC-Philadelphia Metro Chapter. For permission to reprint this article, contact the Managing Editor.
| Whitney Quesenbery, of Cognetics Corporation and--closer to our own hearts--the creator and former webmaster of our own STC-PMC web site, shared some web site design concepts with us at the October PMC meeting. (See Whitney's article in the May 1998 News & Views and on the chapter web site at http://stc.org/region2/phi.) Whitney applied several concepts from cognitive psychology to information site design. These sites might be published on the Internet or a company's intranet and could include online technical publications or updates. Software interfaces could make use of some of these concepts as well.
Basic Design Goals
Cognitive science, which tries to understand how the brain thinks, has codified three basic principles, which can be directly applied to interface design. They are to
- create a meaningful environment for the user
- minimize distractions that intrude upon the user's task
- use visual design to elicit ease of perception.
Meaningfulness
Meaningfulness is the result of creating a direct relationship to the user's task.
An example from Quicken, a successful financial software package. Part of Quicken's success is due to the way they were able to create interfaces that looked like the non-computerized task.
To foster meaningfulness:
- Don't teach by rote or teach actions. Teach concepts. Then the user can solve problems effectively in unexpected situations. For example, don't begin documentation by immediately giving keystroke-specific information.
- Use language effectively:
- Talk in the user's language. Instead of "voice terminal unit," write "telephone."
- Place the most important word at the beginning of a phrase. Tricky, but can be done.
- Surround click targets with additional information. "Click Me for . . ." is not so bad.
- Decrease the user's cognitive load.
Cognitive Load
The last sentence demonstrated a high "cognitive load." I asked you to understand my meaning and at the same time I introduced a new concept. I could have explained first that cognitive load is the amount of mental effort a user must exert to complete a task. In software, however, I want to make concepts transparent. The lower the cognitive load, the more meaningful the software. When the decisions the user must make are simple, not distracting, cognitive activity is directed to the task, not the software.
To decrease cognitive load, reserve short-term memory for tasks, not interface manipulation. To do so:
- do not expect the user to remember the contents of any screen not currently displayed
- do not require the user to remember commands or specialized concepts
- find ways to create clear navigational options
- do not ask the user to make assumptions or predictions
- do not force the user into unnecessary search strategies for functions or data
- do not surprise the user with unexpected consequences of actions
Finally, to decrease cognitive load, optimize perception.
Perception
Perception is the first stage in cognitive processing. The more easily a user can mentally organize a screen and recognize the objects in it, the less cognitive load perception requires.
To optimize perception:
- Use objects that suggest their use. If you want a user to click an object, make sure that it looks clickable. Don't require the user to scrape the mouse across the entire screen to find hot spots.
- Create a mental model of the structure of a task.
- Be consistent in design elements to help the user develop an accurate mental model.
- Use colors and grouping to create easy-to-comprehend perceptual groups.
- Overstate critical cues by emphasis and repetition.
- Use appropriate techniques to focus the user's attention on critical screen elements.
Find ways to provide users with an overview of a process to make the mental map explicit.
Test, Test, Test
Get user input and feedback at every stage of development and keep tests informal to encourage feedback. Then, change the design as soon as testing identifies a problem and re-test.
Where Can You Learn More?
You might like to check out Cognetics Corporation's web site at http://www.cognetics.com or contact Whitney Quesenbery at whitneyq@cognetics.com.
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