Cognition: Memory, Attention, and Learning - Foundations for Designing User-Centered Systems - page 120

Users' initial perceptions of an interface will be influenced by how they store
and process information in short-term memory, and by how the information in
their long-term memory helps them interpret that interface. The way people use a
system will be greatly influenced by how well they can retrieve commands and
locations of objects from memory. Similarly, their feelings of success with a
system will be influenced by their biases in retrieving information about past
successes and failures with the system.
Attention refers to the selective aspects of perception which function so that at
any instant a user focuses on particular features of the environment to the relative
exclusion of others. It plays a central role in interaction, where it often is not
possible to interact with all aspects of the interface at the same time. Some
interfaces require less attention from the user and this can be a good thing if it
allows them to perform more than one task at a time efficiently.
User performance improves through learning. Learning is the most important
process for adapting the user to the machine. There are several ways of describing
learning, but for users the most important aspects of learning are probably learning
facts and learning skills (or procedures) to perform tasks, but there is also learning
to recognize images and perceptual-motor behavior.
5.2 Memory
Memory is one of the most studied areas in psychology. Understanding memory
will help you as a designer to make it easier for users to memorize and later
remember what they want or need to know. We begin by dealing with the structure
of memory, which should enable you to follow the rest of the chapter more easily
(this approach of providing a way to organize what you will learn is itself a result
of memory research).
5.2.1 Types of Memory
Memory can be categorized in several ways. We will first look at memory based
on where it is stored. Then we will examine memories by their content, including
memories about a particular time and place (episodic), about object types
(semantic), about facts (declarative), and about how to do a task (procedural).
While there are other ways to conceptually organize memory, for system design,
the set of categories we present here will give you a broad overview of the issues.
5.2.1.1 Iconic Memory
We can start our discussion of memory with perceptual-based information, spe-
cifically images. Perception, while fleeting, is not completely temporary. There is