Progressive disclosure


Progressive disclosure is an interaction design pattern often used for making applications easier to learn and less error-prone. It does that by defering some advanced or rarely used features to a secondary screen.
The classic example of this pattern in action is from the print dialog box in the Mac OS. When you command the system to print a page, only a small subset of choices are exhibited in the dialog box, and if the user wants more advanced options, they can click on the "Show Details" button and reveal these features in a secondary screen.
In the physical world progressive disclosure is used by modern theme park designers. The long waiting lines for rides can scare away visitors, so only a small segment of the line is made visible from any vantage point. As people move ahead in line, they only get to see discrete portions of the entire line. This design makes the waiting a bit more bearable.

History

, a founding member of the Apple Human Interface Group, wrote in 1985 what could be considered as the seminal idea for selectively disclosing to new users how a system works:
"In the design of interfaces one must also consider carefully how one selectively informs a user about a particular system, providing well-chosen bits and pieces that can constitute a general understanding of a system."