Context: While using the artifact, the user must be
informed of something immediately. This often happens with
Status Display and Control
Panel, especially when they are used in life-critical situations, but
could happen in other primary patterns as well.
Alarms of all sorts
Problem: How should the artifact convey this information
to the user?
Solution: Interrupt whatever the user is doing with
the message, using both sight and sound if possible. Communicate
the message in clear, brief language that can be understood immediately,
and provide information on how to remedy the situation, unless the cultural
meaning of a non-lingual message is so strong that it cannot be mistaken
(like a fire alarm). If the artifact shouldn't be used until the
situation is dealt with, disable all actions until the message is acknowledged.
The user is probably paying attention to something else at the time the
The user may be short of time or under stress, possibly as a result of
the message itself, so they won't be in a good position to stop and think
about how to react.
Normal operation of the artifact after the event happens may be a bad idea.
Too much repetition of a distracting cue can desensitize the user to it.
Use different visual and aural cues for different classes of messages,
so that a tense and distracted user has some basis for distinguishing between
them. Bright colors, motion or flashing, and loud, strident, or shrill
sounds all work to get a user's attention. Stop the alarm after acknowledgement,
or at least let the user mute anything truly distracting.
Resulting Context: Give the user an obvious way
to acknowledge the message. If an audit trail is necessary
or desirable, keep track of the messages over time, as with an Interaction
Notes: This is terribly overused. In truth, it's
rarely the case that a user really must acknowledge a message before they
can resume normal use. If this pattern is used with a non-critical message,
a user's patience will quickly wear thin, and subsequent messages are at
risk of being ignored (as in the boy who cried "Wolf") and bad things may
happen. Use some form of Status Display
for things which aren't critically important; don't shove them into the
user's consciousness uninvited.
There's got to be good reference material out there on this subject.
Comments to: firstname.lastname@example.org
Last modified May 17, 1999
Copyright (c) 1999 by Jenifer Tidwell. All rights reserved.