designing appliances for older persons-老年人(6)

时间：2026-01-13

老年人设计

task-relevant operations only loading working mem-ory [31].

6.Adaptive appliance control

Complex appliances having a high degree of func-tionality may require users to navigate complex hier-archies of displays using a few controls. Such inter-action may be cognitively demanding, as both atten-tion and working memory decline with age. By mak-ing everything needed directly visible in the display reduces demands on working memory, as the need to manipulate or transform information in memory is removed [18,25]. Such a strategy can be counterpro-ductive, due to increasing demands on visual scan-ning. Pak and McLaughlin assert that, instead, the challenge is to present information only as needed, thereby minimizing clutter [25]. That is, the display adapts to the direct needs of the user, avoiding the capture of attention by irrelevant stimuli. We contend that such adaptation should also concord with the cognitive abilities of the users. For example, reducing the number of items displayed may reduce interfer-ence from distractors, which becomes more challeng-ing as one ages.

Another way that an appliance can be made to adapt concerns a guidance system for the device. Cues that assist the user to recall the interaction proc-ess can support older adults in engaging with new appliances that have unfamiliar control structures. By having a different modality for the guidance system to that for controlling the device, the information stream can be segregated from the primary informa-tion in the appliance’s display. By spreading de-mands across attentional resources, confusion arising from competing information streams may reduce. The guidance system should adapt to the learning style and knowledge level of the users. User-specific guidance varies with need; lessening or withdrawing as users gain proficiency.

7.Conclusion

In developing guidelines for designing appliances for older persons, some general implications can be tentatively drawn from the broad discourse on the relationship between cognitive impairment and the features of appliance design. They are:

Evoke an appropriate mental model of an appli-

ance’s operation by designing the features of

graphical objects to reflect, where possible, equivalent objects in similar products

Make objects in the interface distinctly different

from each other and the background

Concentrate objects that require monitoring within the limited field of view of older persons Make the objects in a display immediately ac-

cessible and limit information needed for the

task at hand

For systems with multiple functions, displays that adapts to the current task the user is performing can remove sources of distraction that may capture atten-tion. Limiting the display to objects for immediate use, maintains the focus of the user on the current task. By adapting human-machine interaction to the cognitive abilities of the users, the degree that the system instructs a user can change with the user’s mastery and cognitive capacity. By embodying in-structional assistance within appliances, older adults can be guided in using new technologies, with the ultimate purpose of extending their independence at home and maintaining or restoring their self-efficacy.

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