Today, just thinking aloud...

A minor design conundrum we face is as follows: based on the data we collect, we can see that within certain sets of related features, some of them are used much more frequently than others. Should we ever act on this data by showing only the most-used features in a set?

Let's take three of the most common "sets" of icons in Office: "Bold - Italic - Underline", "Left Justify - Center - Right Justify", and "Undo - Redo".

Conventional wisdom and common practice dictate that wherever one of these icons tread, all of them should appear. I don't think I've ever seen a user interface with just Bold and Italic and not Underline. (At least not one that actually has an underline feature...)

Yet, when you look at the data, Bold is one of the most-used features in Excel but Underline hardly registers. Left Justify and Center are used 100x more than Right Justify in Word. And Redo might as well not even exist next to the towering fame of Undo.

The design challenge comes when we want to pack high-usage commands into a small space, such as when we decide on the default content of the MiniBar or the Quick Access Toolbar. People want efficient access to Bold, but they probably don't need as quick access to Underline. In the past, we've always treated those three icons as a set, but could we get away with only Bold and Italic?

Same with text justification: the data would dictate only putting Left and Center on the MiniBar, perhaps to give way to a more-used command like Highlighter. But would people wonder and criticize why Right Justify isn't there? Do the Left and Center buttons stand alone, or do they require Right in order for people to intuit what they do?

There are other options, of course. We could turn text justification into a dropdown menu, as recent versions of another commercial word processor does. But then you're requiring an extra click to get to any of these features--and at that point, having it on the MiniBar isn't saving you much time anyway.

It is safe to say that we're at least considering dropping a few icons from the MiniBar (only) in order to make room for features people use more.

Perhaps the hardest pill for me to swallow though is having Redo on the Quick Access Toolbar. Undo absolutely belongs there; it is one of the most-used features in Office and it needs to almost feel like part of the frame--something always available regardless of the tab of the Ribbon you're on.

But Redo is used in fewer than 3% of work sessions. And the Quick Access Toolbar is prime real-estate--a place we don't want to take up any extra space whatsoever for superfluous icons. So could you have Undo without Redo? Where would Redo go? It's not used so infrequently as to remove it altogether, so it has to have a home. The current design, in which both Undo and Redo are in the QAT, is the trade-off we feel best with so far.

Does the product's complexity go up much because of the extra Redo icon next to Undo? The good news is "probably not," because you expect to see Undo and Redo together--in this case the extra icon just completes the Back/Forward metaphor seen in so many apps today (especially the web browser.)

I guess a related question would be: Does having a well-known icon missing from a set (say, only Bold and Italic and not Underline) actually cause cognitive dissidence because it feels wrong? These are all interesting questions to look into...