cfry@watdcsu.waterloo.edu (C.Fry - Inst. Computer Research) (01/25/88)
The Psychology of Everyday Things
by
Donald A. Norman
of
Institute for Cognitive Science
University of California, San Diego
Abstract
How do we manage the tasks of everyday life? The traditional
answer is that we engage in problem solving, planning, and
thought. How do we know what to do? Again, the traditional
answer is that we learn, in part through experience, in
part through instruction. I suggest that this view is mislead-
ing. Less planning and problem solving is required than is
commonly supposed. Many tasks need never be learned: the
proper behavior is obvious from the start. The problem space
for most everyday tasks is shallow or narrow, not wide and
deep as the traditional approach suggests. The minimization of
the problem space occurs because natural and contrived proper-
ties of the environment combine to constrain the set of possible
actions. The effect is as if one had put the knowledge required
to do a thing on the thing itself: the knowledge is in the
world.
I show that seven stages are relevant to the performance of an
action, including three stages for execution of an act, three
for evaluation, and a goal stage. Consideration of the rule of
each stage, along with the principles of natural mappings and
natural constraints, leads to a set of psychological principles
for design. Couple these principles with the suggestion
that most real tasks are shallow or narrow, and we start to have
a psychology of everyday things and everyday actions.
The talk itself is meant to be light and enjoyable. However,
there are profound implications for the type of theory one
develops for simulating cognitive computation. There are seri-
ous implications for massively parallel structures (what we
call Parallel Distributed Processing or connectionist ap-
proaches), for memory storage and retrieval via descriptions or
coarse coding, and, in general, for a central role for pattern
matching, constraint satisfaction, and nonsymbolic processing
mechanisms in human cognition. But the main implications of
the work are for the design of understandable and usable objects.
DATE: Wednesday February 3, 1988
TIME: 3:30 p.m.
PLACE: MC 5158
Everyone is welcome. Refreshments served.