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OCR for page 59
3
What New Knowledge Is Needed?
On the bash of the workshop, position papers, and the existing
literature, the Apes of knowledge needed to advance human fac-
tors research ~d engineering for the elderly can be enumerated and
described. For the most part the presang needs are not esoteric
theoretical ad~ces or ascientific breskthroughs~ but merely the
collection of systematic data where none exist. Moreover, no fun-
damental advances in in~restigative methodology are required, but
rather the effective application of already demonstrated research
took. ~ essence, the foBow~g fire major cI"ses of knowledge are
needed.
DIl3TR~RU]?IONAI DATA ON TAS1~13,
131TUAlqONS, AND ACTIVITD:S
It wiD be important to gather more information about the way
older people allocate their time to various activities. Specifically,
what ~ needed are detailed t~me-eample, observational, and survey
data on what people of pervious ages do all day and why. For example,
with respect to transportation, we need to know how older people
get Tom one location to another; where, when, and on what kinds
of roam older people drive; "d what type of location information
they use. Similar information ~ required for other activities such
as daily living tasks sod recreational activities. These data should
be collected at the appropriate level. For example, the application
of t~k-analytic techniques, such as those used by Faletti (1984) in
59
OCR for page 60
60 RUMAN FACTORS RESEARCH NEEDS FOR AN AGING POPULATION
the study of meal preparation, would be useful to collect initial de-
scriptive data on activity patterns and demands. In Faletti's study,
videotapes were made of a sample of people actually preparing meals
in their homes. The tapes were then analyzed in detail In order to
understand the demands (e.g., movements, grips, postures) associ-
ated with meal preparation tasks. Data of this type can be used to
develop models of task performance and to set the stage for more
systematic laboratory or s~mulation-based analyses of human factors
issues associated with various activities. Such data can be used, for
example, to identify activities, equipment, or environmental supports
that wiD serve to unprove task performance.
P1tOB[EM DATA
In addition to understanding patterns of activity performance,
we need to understand which tasks are problematic for c'lder adults
and the types and frequency of difficulties associated with these ac-
tivities. The data collection methods previously cited would provide
valuable information on these questions. However, some answers
Knight be obtained more economically by abstracting those activities
associated with frequent problems and by studying their execution
under controlled laboratory conditions. For example, we know that
using stairs is typically problematic for older adults. It might prove
useful to study stair climbing ~ a laboratory setting where variables
such as stair design features and lighting could be systematically
varied. This would adore the use of instrumentation and protocols to
identify the exact sources of visual, motor, or cognitive difficulty.
Also, it might be beneficis} to compare demands across tasks so
that representative tasks could be selected for more detailed anal-
ysis. This would allow us to generalize with respect to functional
assessment and the application of intervention strategies.
1lUNCTIONAL NORMS
In many aspects of human factors work, data on the distribu-
tion of human characteristics across populations ~ a fundamental
tool. For example, ~ order to design controls such as those found
on appliances or in bathtubs/showers or to determine the apprm
priate height and depth of shelves or cabinets, we need such data
as comfortable reach dimensions, hand dunensions, and hand grip
strength for a broad range of users. Similar data are needed on sen-
sory, perceptual, motor, and cognitive functions. Currently, there is
OCR for page 61
WHAT NEW KNOWLEDGE IS N-FtF1nED?
61
very little dynamic anthropometr~c data available on an age-specific
basis, especially for older cohorts (Stoudt, 1987~.
The utility of normative data on adult populations is twofold.
Fit, this type of data serves as a bash for general analysm and
design and aBows us to design for the whole population. To account
for the entire range of the population, we need to understand to what
extent aging changes the distributions of ~ ous charactermtics. To
date, characteristics of the older population have been largely ig-
nored in engmeenog design, "d thus the elderly often have difficulty
manipulating the designed environment. For this reason many older
adults currently need some type of assistance to complete living ac-
tivities. Secondly, these data would be useful in explicit analysm "d
design to address the specific proble}ns associated with aging, as, for
example, ~ the design of amistive devices.
In addition to normative functional data for older people, data
on the incidence of specific disabilities, dysfunctions, and diseases
are needed. For example, it ~ important to know what percentage
of older adults are afflicted with arthritis and how this affects their
functional capabilities.
Collecting normative data ~ prunarily a matter of systemati-
cally sampling populations of different ages and obtaining apprm
priate measurements. In deciding what measurements to make, it
is important to be guided by information on the frequency with
which activities and difficulties performing the activities occur. For
example, if opening jars is a Sequent activity and causes frequent
difficulty, then the strength distribution of the related twang mo-
tion should be a priority for data collection. As indicated, this type
of information can be gathered from task-analysis and time-sample
data.
When collecting distributional data, it is important to recognize
that the elderly, as a group, are heterogeneous; the changes with
aging are highly variable both within and across individual. This
implies that reported data should represent the variabilities at each
age as wed as averages. It also unplies that it ~ unportant to under-
stand what functions and abilities increase with age as well as those
that decline.
FOCUSED HUMAN FACTORS litESEARCH ISSUES
Ultimately, we need answers to specific scientific and practical
OCR for page 62
62 RUMAN FACTORS R~513ARC~ NEEDS FOR AN AGING POPULATION
questions about identified hurrah factors and aging problems. Sur-
vey and t~k-~ysm Formation will fib in gaps In our ex~t~g
knowledge base ard win identify the problems and some of their
parameters. However, solutions to these problems win ~ most cases
require additional, more narrowly direct research. For example, it
is known that older people have difficulty learning computer-based
text editing and that they tend to have increasing difficulty with
complex cognitive tasks. But to understand the relationship be-
tween these To pieces of information and to fired a way to make
computer tex~editing problerna easy for the elclerly, we need to know
which aspects of the tex~edit~g task are especially demon cling for
them. similarly, we currently know that certain types of automo-
bile accidents are more common among older people, and we know
that older people have, on average, deficiencies in a variety of visual
and motor abilities. Yet we still lack information regaling which
aspects of driving cause stress to age-related abilities. Similar issues
can be ramed about stairways. It is not the intention or purpme of
this report to provide an exhaustive list of research questions but to
suggest some examples for initial research. As we begin to collect
more detailed information on the activity patterns of older people,
additional areas of specific research will be identified.
The routes for de iiing tenth specific problems, once identified,
may be differentiated as remediation (eliminating the dysfunction or
the environmental problem); compensation (fining some alternative
way to achieve the same goab); adaptation (restricting one's beha~r-
ior pattern to deal with the problem despite its difficulties); and
accommodation (learning to substitute other goad ~d activities for
those that are unachievable). AD of these solution paths may involve
significant humor factors research, analysis, add design.
DESIGN PRINCIPLES AND EXAMPLES
Knowledge that would help reduce the number of problems that
the elderly face would cons~t of actual solutions to a representative
sample of design problems. If several important t~k-related prom
letrm ~n~rolv~ng perceptual difficulties (e.g., reduced night vision for
driving); cognitive difficulties (e.g., reduced ability to perform com-
plex tasks such as text editing); ~d motor problems (e.g., street
crossing) could be reduced by systematic efforts at analyze and re-
design, both the methodological examples ~d the substantive design
techniques would be likely to generalize to many other problems. A
OCR for page 63
W]IAT NEW KNOWLEDGE IS NF!F!nED,
63
few such successes might also serve to stimulate greater efforts on
the part of researchers and design ere.
The two most important contnbuto" to good human factors de-
sign are task versus ability analysm add iterative design. By iterative
desigm we mean a process in which design ideas are implemented in
an easily modifiable prototype or simulation; tested on a represents
tire sample of actual users; modified according to obeer~red successes,
failures, and~mpremions; ardtr~ed again. Su~design methods have
been found to be extremely effective and cost efficient, especially in
the development of computer-based systems where the flexibility and
power of the machine make extensive adaptation to the user fe~i-
ble (Gould, Boies, I,e~ry, Richards, and Schoonard, 1987; Landauer,
1988; Good, Whiteside, Wilson, and Jones, 1984~. Fourfold to ten-
fold improvements ~ speed and accuracy resulting from a few weeks
of effort are common with this approach. The essential ingredient
is aformative evaluations to guide design early in the invention ~d
development phase. Given that the evaluation must Solve people
with the same characteristics ~ the eventual users, and given that
most systems, products, =d environments are used by a wide range
of users, older adults must be included in such iterative testing.
Representative terms from entire chapter:
meal preparation
