Cognition: Mental Representations, Problem Solving, and Decision Making - Foundations for Designing User-Centered Systems - page 161

Chapter 6
Cognition: Mental Representations,
Problem Solving, and Decision Making
Abstract There are several higher level structures built upon the basic structures
of memory, attention, and learning in the user's cognitive architecture. These
representations and behaviors include mental models, problem solving, and
decision making. These structures and processes form the basics of higher level
cognition when interacting with technology, and describe some of the ways that
users represent systems and interfaces, and how users interact with and use sys-
tems. 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. Problem
solving is used when it is not clear what to do next. Problem solving uses mental
models, forms a basis for learning, and can be supported in a variety of ways.
Decision making is a more punctuated form of problem solving, made about and
with systems. It is not always as clear or accurate as one would like (or expect),
and there are ways to support and improve it. There are some surprises in each of
these areas where folk psychology concepts and theories are inaccurate.
6.1 Introduction
When people interact with artifacts, even for the first time, they usually have some
idea of what to do. If it is a piece of electrical equipment, they may first look for
the on/off switch, for example, and then press that. The way that people interact
with artifacts is governed by their mental representation of that artifact. These
mental models develop over time: as people use the artifact more and more, they
learn more about how it works and refine their mental model accordingly. The
mental models can be either structural (based on the structure of the artifact in
terms of its components) or functional (based on the behavior of the artifact).
As the complexity of artifacts increases, it becomes harder to develop a
complete, accurate structural mental model of them. If you are someone who
drives a car but takes it to someone else for maintenance, for example, the chances
are that you have a relatively simple functional mental model of how the car