Remembered State

Examples: Bad Examples: Context: The artifact lets users enter information (e.g. Form), set its state in various ways (as with Control Panel or WYSIWYG Editor), or customize it; and the artifact is likely to be used again soon by the same user.

Problem:  How can the artifact help save the user time and effort?


Solution:  Design the artifact so that it can remember its state from session to session.  If multiple users are likely to use it, make sure the state is saved on a per-user basis.  The state should be recalled and reconstructed without any user intervention, so that the illusion of continuity is convincing. Keep in mind, though, that sometimes a user may not want the state to be recalled!  Give the user an option to start fresh if they choose.

Chances are, not all state needs to be saved; users may not care about some of it, like keyboard focus or mouse position. Try to balance the time and resources needed to implement Remembered State against the value it adds to the user's experience.  Usability testing may help you find this balance.

Resulting Context:  All of the user-modification patterns can be implemented with Remembered State:  User Preferences, to let a user set up simple options like fonts and colors; Personal Object Space, for extensive custom layouts; Scripted Action Sequences, to record series of actions; User's Annotations, for comments and other auxiliary help-style information; and Bookmarks, to keep track of landmarks in Navigable Spaces.  They are all pretty much useless without Remembered State to carry them from session to session.  If you've got a good mechanism for this pattern, consider using it for these others, if they make sense in the design.

Remembered State can also be used to establish a set of Good Defaults for things like a Form or a Control Panel.  What worked last time for a user is likely to work again next time, under some circumstances.

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Last modified May 17, 1999

Copyright (c) 1999 by Jenifer Tidwell.  All rights reserved.