designing appliances for older persons-老年人(5)

老年人设计

5.1.1.Mental models

D ue to the difficulties older adults experience in attending displays, discerning device features, and processing information in working memory, cogni-tive workload associated with learning may be exces-sive. Consequently, the progressive development of well-formed mental models may be hindered. How-ever, if users of the appliance can recognize a famil-iar functional relationship then their cognitive work-load may reduce [28]. That is, by exploiting users’ understanding of familiar technologies in appliance design, users may transfer learned patterns of control between old and new technologies [25]. Training can also reduce demands on working memory.

By designing appliances in a way that exploits ex-isting mental models of users, some cognitive load may be shed to externalized prospective memory. In effect, the cognitive system would then combine in-ternalized representations of control and externalized memory aids.

5.2.Supporting working memory through externalization

Effectiveness of technology correlates with users accessing appropriate mental models that guide de-vice use. In the case of new devices, successful for-mation and use of mental models depends on persons holding and working with information in working memory.

Often seniors can cope better if information that they have to remember is externalized. Commonly persons, whether young or old, use external-memory aids for remembering future tasks [14]: For example, jotting notes on a pad or locating objects somewhere that will jog memory. Such practices can counter age-related decline in prospective memory to such an extent that older adults can outperform unaided younger adults [4,25]. However, the process of ex-ternalizing information requires care. Setting a suit-able degree of externalization is difficult, as fixed methods or levels of externalization will not be ap-propriate for all users. Zhang argues that externaliza-tion goes beyond being a mere memory aid: “They are intrinsic components of many cognitive tasks; they guide, constrain, and even determine cognitive behavior” [36]

D esigners can provide externalized cues, in the form of Gibsonian affordances, to compensate for cognitive deficiencies by transferring information from memory to the world. Controls or display items on an appliance may provide the means for potential possibilities, but they only become affordances if users realize their potential. A latent predisposition for an applied method of device control (pre-existing mental model) exists when operating a device similar in look or functionality to one a user is familiar. Cognitive workload in using a new product may re-duce significantly by exploiting latent predispositions from familiar appliances.

Information that may help older operators use an appliance pertain to the operation’s goal, current state, and remaining steps to the goal. Cues for any combi-nation of these may assist older adults control the device. The challenge in designing externalized cues lies in defining the method of signaling and determi-nation of singular or combined forms of cueing that are most effective given the state of cognition of the user.

5.3.Training

In discussing cognitive capacities in section 2, we espoused multisensory training strategies to counter age-related functional decline. D isplaying control and response stimuli in more than a single sensory mode may help the comprehension of, and reaction to, presented information [13,19].

There are different approaches to learning a new skill. Strategies in developing a skill differ between learning-oriented and performance-oriented persons. Training programs should be directed towards the form of learning orientation. Kozlowski et al contend that the difference is between learning directed to-wards mastery of the skill itself, versus, activity di-rected towards demonstrating to others their compe-tency [11]. The former take an active self-motived approach. The latter may avoid situations that chal-lenge their abilities, including training program.

In Georgia, USA, research into the use of Auto-mated Teller Machines by older adults showed that users taught the procedural steps outperformed users undergoing conceptual training. These findings held for both learning and retention over 24 hours. Con-trastingly, the type of training experienced by young-er users did not affect their performance [16,23]. These studies suggest that instructional design can benefit many older adults in adapting to technologies and new forms of interaction. Moreover, demand on working memory can be significantly reduced through training. Elderly persons may benefit more from training in which they study worked examples instead of conventional means-ends analysis, due to

P.G. Higgins and A. Glasgow / Development of Guidelines for Designing Appliances for Older Persons

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