User interface design

AskTog has a nifty article about user interface design :

[AskTog: A Quiz Designed to Give You Fitts]:

It’s got bits about menubars and how to make stuff easy to click on.

> Excerpt:
Microsoft Toolbars offer the user the option of displaying a label below each tool. Name at least one reason why labeled tools can be accessed faster. (Assume, for this, that the user knows the tool and does not need the label just simply to identify the tool.)