Ergonomics and Aging - Fundamentals and Assessment Tools for Occupational Ergonomics - page 408

telephone voicemail menu systems to check on work-related responsibilities or to inquire about the
status of their paycheck are required to store and process the menu options while attempting to make
navigational decisions. If the structure of the menu system is very broad such that a large number of
options must be considered before a choice can be made, older adults may find themselves forgetting
the content of the options because their working memory capacity is being taxed. As only one option
can be chosen at a time, it must be appropriate for the goals of the older adult. Thus, all options
other than the desired option must be considered as unwanted information and should be ignored.
Furthermore, the speed of menu option presentation is another factor to consider when designing
phone menu systems because older workers may be slower to process information than younger
coworkers.
System modifications used to combat the age-related decline in working memory should result in
increased usability of the telephone menu system. Reducing the number of menu items that have to
be considered at each level of menu hierarchy should reduce working memory demands (Reynolds
et al., 2002). Yet another solution might be to present the most commonly requested menu items
first, thereby reducing the need to ignore unwanted options. Slowing the speed of menu item presen-
tation may also result in a more usable menu system for older adults because they will be given the oppor-
tunity to process all of the available menu options (Reynolds et al., 2002).
Semantic memory refers to the store of factual information that accrues through a lifetime of learning.
Remembering the meaning of symbolic codes used in an account invoice, the telephone number for the
employee lounge, and the route to the purchasing department are all examples of semantic memory
because this is information that was acquired through experience. Age-related differences in the organ-
ization and use of semantic information are slight or nonexistent, although it may take older adults
longer to learn new information. Thus, semantic memory remains intact throughout the lifespan
(Light, 1992). When new information is encountered, it is often interpreted in the context of the pre-
existing knowledge base.
Working memory and semantic memory are forms of retrospective memory or memory for past
events. Prospective memory refers to remembering to do things in the future. For example, remembering
to check a gauge at a certain time or to attend a meeting requires one to remember a task that has to be
performed at some time in the future. Event-based and time-based prospective memory tasks vary by the
demands of the task characteristics (Einstein and McDaniel, 1990). For an event-based task, a cue in the
environment reminds one to perform a prospective task (e.g., placing a note next to the computer as a
reminder to write an office memo). In this context, cues in the environment act as mnemonic or environ-
mental support that increases the likelihood of remembering the prospective task. In contrast, time-based
tasks lack environmental support because they have few external cues. Time-based tasks are largely self-
initiated and require one to perform an action at a certain time or after a specified amount of time has
elapsed (e.g., remembering to make a phone call at 4:30). Age differences in prospective memory are
usually much greater for time-based than event-based tasks (Park et al., 1997). Hence, older workers
are less likely to exhibit declines when performing event-based tasks.
17.5 Decision-Making
On a daily basis, workers encounter situations that require them to make decisions such as when to sche-
dule a meeting or which lever to use to make a particular adjustment. While these decision contexts seem
quite different, they both rely on a decision-making process that requires people to consider multiple
pieces of information, interpret that information in relation to some goal, then select the best course
of action from the alternatives available. Although decision-making is obviously an important cognitive
factor in the workplace, relatively little is known about the decision-making capacity of older adults
because it has been neglected in research on aging (Sanfey and Hastie, 2000).
Of the few studies that have been conducted, it appears that older adults consider fewer pieces of infor-
mation so as not to tax working memory when determining courses of action (Johnson, 1990) and that