Multiple levels of progressive disclosure

How many levels of progressive disclosure are acceptable?

Interfaces that include more than two levels of disclosure have low usability because users often get confused and may get lost when moving between levels of complexity.

How can you avoid adding extra levels of complexity?

• Reconsider your advanced features. Smart sorting and regrouping can do wonders and make the interface easier to navigate. When in doubt, talk to your users and observe whether they see the difference between levels and experience any trouble navigating between them.
• Consider adding 2 levels of secondary disclosure. It may prevent adding the third level, but it's still not the best idea from the usability perspective since multiple controls for advanced options can disorient users.

When you add a third level of disclosure or two secondary levels, you should give labels more thought. By any means, avoid the ambiguous Learn More/See More/Read More buttons. While they may work in a typical situation of two-level disclosure, in a more complex interface, they will only frustrate users and force them to leave.