Progressive Disclosure by Jakob Nielsen (Usability Expert)

Tue, Dec 05, 2006

I just read an article from Jakob Nielsen, a usability expert. The amazing article -- "Progressive Disclosure (Progressive Disclosure)": states that Progressive disclosure defers advanced or rarely used features to a secondary screen, making applications easier to learn and less error-prone.

_Excerpts from the article;_

Interaction designers face a dilemma:

* Users want power, features and enough options to handle all of their special needs.
* Users want simplicity; they don't have time learn a profusion of features in enough depth to select the few that are optimal for their needs.

Progressive disclosure is one of the best ways to satisfy both of these conflicting requirements. It's a simple, yet powerful idea:

# Initially, show users only a few of the most important options.
# Offer a larger set of specialized options upon request. Disclose these secondary features only if a user asks for them, meaning that most users can proceed with their tasks without worrying about this added complexity.


In a system designed with progressive disclosure, the very fact that something appears on the initial display tells users that it's important.

*For novice users*, this helps prioritize their attention so that they only spend time on features that are most likely to be useful to them. By hiding the advanced settings, progressive disclosure helps novice users avoid mistakes and saves them the time they would have spent contemplating features that they don't need.

*For advanced users*, the smaller initial display also saves them time because they avoid having to scan past a large list of features they rarely use.

Progressive disclosure thus improves three of "usability's five components (Usability 101: Introduction to Usability)": -- learnability, efficiency of use, and error rate.

*Usability Criteria*

There are two things you must get right when designing for progressive disclosure:

* You must get the right split between initial and secondary features. You have to disclose everything that users frequently need up front, so that they only have to progress to the secondary display on rare occasions. Conversely, the primary list can't contain too many options or you'll fail to sufficiently focus users' attention on truly important issues. Finally, the initial display can't contain confusing features or you'll slow down user performance.
* It must be obvious how users progress from the primary to the secondary disclosure levels --
# First, make the mechanics of this operation simple. For a website, follow the guidelines for visualizing links. For an application, place the advanced features button in a clearly visible spot.
# Second, label the button or link in a way that sets clear expectations for what users will find when they progress to the next level. (In other words, the progression should have strong information scent.)

*Managing Complexity*
Progressive disclosure and staged disclosure are both strategies to manage the profusion of features and options in modern user interfaces. They are both more than 20 years old and have proven themselves useful in countless applications, and even some websites. Jacob urges us to try them -- but stay aware of their weaknesses.

Via -- "Jakob Nielsen (Jakob Nielsen)":