Cognition is the mental action or process of acquiring knowledge and understanding, through thought, experience, and the senses. Memory is an important part of cognition (in addition to attention, decision making and learning, each of which is discussed separately). There are different kinds of memory and each is affected differently by the ageing process. For example, procedural memory (remembering how to do things) is generally not affected by ageing. People of all ages are able to learn new skills, if they are provided with adequate time, instruction and assistance, and they are able to practice these skills over time. These factors should inform UI design for seniors (“UI” is shorthand for “user interface”).
Other types of memory do suffer as we age. Short term or active memory (capacity for holding, but not manipulating, a small amount of information in mind in an active, readily available state for a short period of time – 18 to 30 seconds) is particularly vulnerable to the ageing process. One effect of reduced short term memory in seniors is in problems with text comprehension, especially of longer or more complex passages. This is important in UI design for seniors.
Episodic memory is our memory of autobiographical events (times, places, associated emotions, and other contextual aspects) that can be explicitly stated. They allow an individual to figuratively travel back in time to remember the event that took place at that particular time and place. Episodic memory does not naturally diminish with age. However, it can be impaired by illness, medication, depression and dementia – all of which seniors are prone to.
Long-term memory requires learning and repetition to become fixed, but once stored these memories can last a long time and be retrieved by triggers or cues. Knowledge may be in different forms, such as remembering what things are; how to do something; or remembering linked episodes of verbal and visual interactions that occurred in the past. Deliberate recall of previously encountered material becomes harder with age; although recognition of previously encountered items is not greatly affected if the items are simple. Age related long-term memory decline can also cause problems in remembering if a task has been completed or if it still needs to be done. Understanding the differences in how memory works with material vs. items vs tasks is critical in good UI design for seniors.
Working memory allows us to reason about visual features and spatial relationships. Working memory is used to manipulate and rearrange information within the span of attention – usually 18 to 30 seconds – before it decays. Information can be held in different forms, such as the verbal meaning of words (e.g. a word “phone”), the visual or spatial content (e.g. “a phone icon”) or its episodic context (e. g. “it’s what I press to make a phone call”). Older people often have difficulty manipulating the contents of their working memory. This means that they may have trouble understanding how to combine complex new concepts in a product or steps in a user interface.
Remembering that the perceptual cues in front of you are similar to a stored memory is called recognition, while remembering something stored in memory from different cues in front of you is called recall. Identifying whether you have seen a UI button before requires recognition, while remembering what it does requires recall. Recall generally takes longer than recognition. Older people are likely to have problems with recall. Structuring of memories may be worse in less educated older adults. Older people have problems in using context to prompt recall memory, as distinct from recognition. Seniors have less ability to inhibit irrelevant memories. And attempts to recall information are more affected by anxiety, which older people are more prone to have when facing a technology user interface.
Prospective memory (remembering to perform a planned action or intention at some future point in time) also suffers with ageing. This is particularly relevant for habitual tasks, like remembering to take medication at the right time every day, or to check for voice, text or email messages. Older people often use written notes, calendars and diaries to mitigate declines in prospective memory.
According to the Alzheimer’s Association one in nine elderly adults age 65 and older (11%) has some form of Alzheimer’s disease. About one-third of people age 85 and older (32%) have some form of Alzheimer’s disease. Prevalence rates in the US of all forms of dementia (including Alzheimer’s) have been estimated at 13.9% of people age 71 and older. And more women than men have Alzheimer’s disease and other dementias. Almost two-thirds of Americans with Alzheimer’s are women.
Many older adults may not experience Alzheimer’s disease or other dementias, but may experience some form of mild cognitive impairment (an intermediate stage between the expected cognitive decline of normal ageing and the more serious dementia). Common experiences associated with mild cognitive impairment can include trouble remembering the names of things that were recently learned, trouble remembering the flow of a conversation or task, and an increased tendency to forget where things are located. Other forms of cognitive diminishment also arise in greater proportions in older people. For example, the effects of stroke, the incidence of which increases with age, can result in conditions similar to mild cognitive impairment.
- Emphasize recognition over recall in UI design for seniors. Showing users things they can recognize improves usability over needing to recall items from scratch because the extra context helps users retrieve information from memory. You can promote recognition by making information and interface functions visible and easily accessible, for example, by providing thumbnail images of pages already visited in a web interface. Jacob Neilson provides excellent guidance on this.
- Employ skeuomorphism (the design concept of making items represented resemble their real-world counterparts) as much as possible, for example, email represented by an envelope icon.
- Use predictable user interface structure to assist memory in good UI design for seniors. The structure of screens or pages should be shallow. Each complicated screen should have a descriptive label with meaningful instructions clearly displayed.
- Reduce the number of information chunks that need to be kept in mind at any given time. Try not to exceed 5 information chunks at one time in your UI design for seniors.
- Do not ask older people to remember material from one user interface screen or page to another. Avoid splitting tasks across multiple screens or pages if they require memory of the content or actions on previous screens or pages.
- Provide an obvious mechanism that allows users to get back to their previous location or home when navigating user interface structure. Use “home pages” and “back buttons” to make it easier to navigate to known reference points.
- Navigation elements should be visible all the time. Avoid pop-up, slide-out and other hidden menus.
- No more than 7 or 9 items should be located in a menu. Longer lists of items should be split into groups.
- Where hierarchy is used, ensure that the current location within the overall hierarchy is always evident (e.g., using a breadcrumb trail) and try not to exceed three levels.
- Supplement icons, buttons and other user interface elements with text labels.
- Each distinct button should have only one function in a given user interface. Similarly shaped buttons, which have different functions should use different colors, graphics and text to help differentiate between the functions.
- Text labels should be short and easily understandable. Every label should be in written language, for example “today” or “yesterday” would be better than just numeric date representation.
- In UI design for seniors avoid using different terms for similar actions, for example, “Add Contact” and “Add Friend”.
- Introduce user interface features gradually to prevent cognitive overload. This can be done with how the user interface is designed, and with how learning materials are structured and organized.
- During longer user interface tasks, give clear feedback on status, progress and reminders of goals.
- Provide reminders and cues that have a built-in memory reinforcement mechanism for user interface actions. These reminders and cues (mnemonics) can be constructed using imagination, association and location. Combinations of colors, graphics, words and sounds are commonly used in reinforcement mechanisms.
- Avoid complete user interface redesigns, or allow users to continue to use the prior user interface versions.