Idiosyncratically Modal Behavior

Many times user testing indicates that a user population divides relatively equally on the effectiveness of an idiom. Half of the users clearly prefer one idiom, whereas the other half prefers another. This sort of clear division of a population's preferences into two or more large groups indicates that their preferences are idiosyncratically modal.

Development organizations can become similarly emotionally split on issues like this. One group becomes the menu-item camp while the rest of the developers are the butcon camp. They wrangle and argue over the relative merits of the two methods although the real answer is staring them in the face: Use both!

When the user population splits on preferred idioms, the software designers must offer both idioms. Both groups must be satisfied. It is no good to satisfy one half of the population while angering the other half, regardless of which particular group you or your developers align yourselves with.

Windows offers an excellent example of how to cater to idiosyncratically modal desires in its menu implementation. Some people like menus that work the way they did on the original Macintosh. You click the mouse button on a menu bar item to make the menu appear; then—while still holding down the button—you drag down the menu and release the mouse button on your choice. Other people find this procedure difficult and prefer a way to accomplish it without having to awkwardly hold the mouse button down while they drag. Windows neatly satisfies this by letting the user click and release on the menu bar item to make the menu appear. Then the user can move the mouse—button released—to the menu item of her choice. Another click and release selects the item and closes the menu. The user can also still click and drag to select a menu item. The brilliance of these idioms is that they coexist quite peacefully with each other. Any user can freely intermix the two idioms, or stick consistently with one or the other. The program requires no change. There are no preferences or options to be set; it just works.

Starting in Windows 95, Microsoft added a third idiosyncratically modal idiom to the menu behavior: The user clicks and releases as before, but now he can drag the mouse along the menu bar and the other menus are triggered in turn. Amazingly, now all three idioms are accommodated seamlessly. The Mac now, too, supports all three of these idioms.