About Face 2.0(c) The Essentials of Interaction Design

Expanding dialog boxes were big around 1990 but have declined in popularity since then, largely due to the omnipresence of toolbars and tabbed dialogs. You can still find them in many mainstream applications, such as the Find dialog in Word.

Expanding dialogs unfold to expose more controls. The dialog shows a button marked More or Expand, and when the user clicks it, the dialog box grows to occupy more screen space. The newly added portion of the dialog box contains added functionality, usually for advanced users or more complex, but related, operations. The Find dialog in Word is a familiar example of this idiom and is shown in the previous chapter, in Figure 30-2.

Expanding dialog boxes allow infrequent or first-time users the luxury of not having to confront the complex facilities that more frequent users don't find upsetting. You can think of the dialog as being in either beginner or advanced mode. However, these types of dialogs must be designed with care. When a program has one dialog for beginners and another for experts, it all too often simultaneously insults the beginners and hassles the experts.

Most expanding dialogs are implemented so that they always open in beginner mode. This forces the advanced user to have to promote the dialog each time. Why can't the dialog come up in the appropriate mode instead? It is easy enough to know which mode is appropriate: It's usually the mode it was left in. If a user expands the dialog and then closes it, it should come up expanded next time it is summoned. If it was put away in its shrunken state last time, it should come up in its shrunken state next time. This simple trait could make the expanding dialog automatically choose the mode of the user, rather than forcing the user to select the mode of the dialog box. The Find dialog from Word does exactly this. Bravo, Microsoft!

For this to happen, of course, there has to be a Shrink button as well as an Expand button (or a Less as well as More, as in the Find dialog). The most common way this is done is to have only one button, but to make its legend change between More and Less as it is clicked. Normally, changing the legend on a button is weak because it gives no clue as to the current state, only indicating the opposite state. In the case of expanding dialogs, though, the visual nature of the expanded dialog itself is clear enough evidence of the state the dialog is in.