Modes of User Assistance
One can think of user assistance as falling into one of two modes: pulled UA and pushed UA.

In pulled UA, the user takes action to summon or access the user assistance.
Examples of pulled UA include:

• Manuals
• Help files (accessed by clicking on Help in the menu or a Help icon)
• What's this?
• Search

In pushed UA, the system detects a situation and provides assistance proactively. Examples of pushed UA include:

• UI instructional text that is part of the static UI display, e.g., examples of date formats next to date entry fields
• Field and control labels
• Default instructions in dropdown lists, e.g., "Select carrier" as the default selection in a dropdown list for selecting cell phone carrier.
• Roll-0ver techniques such as tool tips (which can turn into pulled UA as the user comes to expect the technique and deliberately mouses over an object to get information about that object)
• Contextual embedded help
• Did you know? or Tip of the day messages
• Context-sensitive help activated by clicking an icon
• Linked help, e.g., Tell me more... links that expand on information provided in the UI.

Pulled UA requires that the user be in a state of explicit ignorance, that is, the user does not know something BUT is aware that she does not know that something. It also requires that the user be able to articulate, at least in general terms, the question she wants answered. For example, a procedure on How to make an unordered list is going to be accessed only by someone who knows that lists can be bulleted for better effect AND who would know that such a list is called an unordered one.

Pushed UA can be very effective when the user is in a state of tacit ignorance, that is, the user does not know something and is also unaware that she does not know it, or that it even exists to be known.

Designing and writing pulled UA require attention to content organization, taxonomy creation, indexing, and good search capabilities. Designing and writing pushed UA requires that the user assistance be more integrated with the application and act more like part of the product.