Cognition: Mental Representations, Problem Solving, and Decision Making - Foundations for Designing User-Centered Systems - page 192

Thus, it is a rare and unhappy individual who knows that their answers are
inadequate. For example, the knowledge to judge whether a sentence is gram-
matical, a word is correctly spelled, a diagram is well drawn, or program well
written will be highly correlated with the ability to generate the correct behavior.
So people who generate ungrammatical sentences or perform poorly on these other
tasks are likely to be unable to know that they are ungrammatical.
What does this mean for users and designing for users? It means, on average,
users will think that they know more than they do. They will be overconfident
when performing tasks, and they will not always use the right cues to judge their
knowledge.
Good design can help provide more feedback on performance, and could also
provide education along the way about how to correct problems. Noting that
''Error 23 occurred'' does not help. Noting that ''Removing disks without un-
mounting them can lead to disk errors'' is a step in the right direction because it
provides a way for users to learn from their errors through feedback.
6.5 Summary
This chapter has given you a broad understanding of how users think by providing
high level descriptions of user behavior. Mental models, problem solving, and
decision making all depend on the simple architectural mechanisms introduced in
earlier chapters. When users interact with technology they depend on the high
level cognition we have described. By understanding the capabilities and limita-
tions of high level cognition you should be better equipped to understand some of
the ways that users can represent systems and interfaces and how they interact with
and use them.
Mental models are used to understand systems and to interact with systems.
When the user's mental models are inaccurate, systems are hard to use. Designers
can attempt to understand users' initial mental models. Designers can then either
design to support users with those models, or they can help educate users to
acquire more appropriate mental models.
Users problem solve when it is not clear what they should do next. Problem
solving uses mental models, forms a basis for learning, and can be supported in a
variety of ways. Systems that provide appropriate information to users can help
with problem solving. When users are found to problem solve, it may be appro-
priate to modify the interface to support behavior to make it include less problem
solving, to provide feedback to support problem solving such as distance to the
goal, or to perform the task for the user.
Decision making is a more punctuated form of problem solving, made about
and with systems. It is not always as accurate as outside observers would expect it
to be. There are ways to support and improve decision making. Short-term, there
are biases to avoid encouraging in the interface. Long term, providing feedback
about past decisions and their accuracy can help users.