
Eric Schaffer,
Ph.D., CPE, is CEO and Founder of Human Factors International, Inc.
He has been involved in creating and teaching software design for more than 14 years. He can be reached by e-mail: eric@humanfactors.com

John Sorflaten,
Ph.D., CPE, started out writing and directing training films and documentaries then switched to UI design.
"A screen is a screen," he says. He works at Human Factors International, Inc. and can be reached by email at john@humanfactors.com
| Key Tips for User-Centered Design Article Download (31K pdf file) |
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PRINCIPLE |
EXPLANATION |
|---|---|
| Windows | |
| Use a structure that controls window thrashing and window pile-up. | Anticipate user needs. Size and position windows to be useful immediately when opened. Use a UI architecture that avoids the need for window thrashing (E.g., folders, notebook, and context switch). It costs users time to activate, resize, reposition and orient to the new window. (See our GUI design column on menus.) |
| Try to reserve pop-up windows for infrequent use. | A pop-up dialog box provides extra screen "real estate". But reserve it for occasions that occur rarely (5% of the time or less). |
| Use pop-up windows to keep context rather than to proliferate variety of tasks. | Help users keep track of their work flow with the main window in the background and an associated dialog box in the foreground. Have only one pop-up open at a time, where possible. |
| Avoid small windows. | Let users see as much context as possible. Limiting context is as bad as having your long-range view of the road reduced by fog. |
| Avoid frequent pop-ups. | Use an additional primary window instead of numerous pop-ups. Less fragmentation of data lets user see context better and consequently work faster. |
| Flag users about data in an unopened pop-up dialog box. | On the primary window, provide an "indicator icon" on the pop-up button. The icon informs users whether or not data exists in the pop-up. This saves the user from needlessly opening the pop-up to check for data. |