For most older adults, reasoning ability declines with age.  Speed of mental processing slows.  There is less ability to recall relevant information through associations with information presented in a problem (associative memory).  When faced with problems, elderly people rely more on existing knowledge and are less able to work out new solutions (crystallized versus fluid intelligence).  For these and other reasons discussed below, older adults are generally slower and less able with decision making than younger people.  These factors should inform UI design for elderly people.

Losses in decision making ability in older people tend to be correlated with losses in visual thinking performance.  Visual thinking is the ability to perceive and think about visual objects and spatial relationships in two and three dimensions.  Some key visual thinking functions that should be considered in UI design for elderly people are:

• Filtering and extracting information from the low-level sensory information that eyes receive, in order to identify and group objects.
• Relating objects and icons to each other according to their spatial position, (that is, understanding the relationship between UI elements and their positions on a screen).
• Rotating drawings, symbols or text in two dimensions, or objects in three dimensions.
• Grouping objects according to properties such as their shape, color or spatial alignment.

As visual thinking declines, older people will have more trouble adapting to minor inconsistencies in a user interface model (e.g., white space that behaves differently from another white space).  They are also slower to recognize items (but this effect is reduced for familiar items).

The ability to detect small movements declines with age.  Older adults make poorer estimates of speed and time of arrival, have poorer depth perception and estimation, and have poorer perception of three-dimensional information.  Older adults have poorer pattern recognition, less recognition of embedded or incomplete figures, and are less able to filter out irrelevant items.  These problems are all related to losses in visual thinking performance and need to be considered in UI design for elderly people.

Seniors adopt a more conservative strategy with regard to risk taking, and will make decisions more slowly when under pressure or in a state of high anxiety.  New automatic responses are harder to form for seniors and existing automatic responses are harder to suppress, if necessary due to changed circumstances.

As a general rule, elderly people require 50-100% more time for typical user interface tasks than adults under 30.  Young people are able to process decision factors more quickly than old people, and they tend to weigh a lot of options before settling on one.  Older adults process fewer factors, linearly and more slowly; and they tend to emphasize prior knowledge (perhaps because they’ve had more time to accumulate it).  They also place more value on expert opinion.  These are all important considerations in your UI design for elderly people.

Mitigation Strategies:

• The user interface navigation model should be consistent throughout. There should be a standardized way for navigating between screens.  Back buttons should be in consistent locations and behave predictably.  Avoid different page and screen layouts and complicated navigation structures.
• Make it as easy to find things in the user interface. Make the structure of the user interface as shallow and visible as possible.  Place the most important and frequently needed user interface elements closer to the surface of the user interface architecture.  Avoid deep menu structures and nonlinear paths through the information.  In a website, provide a site map and make it accessible from every page.
• Ensure that all actions are easily and immediately reversible, and try to constrain the availability of actions that would result in undesirable or irreversible outcomes. Prioritize shortcuts to previous choices ahead of new alternatives in your UI design for elderly people.
• Make it easy to see what buttons and other clickable shapes do. Clearly label buttons and other clickable shapes using simple text and terms that older people are familiar with.  If embedding an image or symbol in a button or other clickable shape, make sure the image or symbol is “task relevant”.  Avoid the use of images and symbols that might be unfamiliar to older adults with lower technology experience.
• Make it obvious what is clickable and what is not. However, avoid user interface elements that change appearance – these tend to be harder to understand and tend to worry older users.  For example, avoid “flat graphics” that only take on the appearance of buttons with a mouse- over.
• Make it easy to see when a button or other clickable shape has been clicked in your UI design for elderly people.
• Make the user interface easy to skim or scan. Use visual cues to direct users’ attention to important user interface elements.  Ensure that task-supporting keywords stand out.  Position the most important and frequently used elements “above the fold” and close to the center of the screen or page rather than in the margins.  Make it easy to distinguish content from advertising.
• Aim for consistent positioning of controls in each part of your application. Older people are better at searching when there is consistent positioning of search targets.
• Visually group related functions. Use shapes, colors and alignment to assist visual recognition of features that share some similarity, thereby reducing the time and working memory required to locate a desired feature.
• Arrange clickable user interface elements in one dimensional layouts (vertically or horizontally). Avoid two dimensional layouts in your UI design for elderly people.  Avoid random patterns of choices. Older people perform better on searches of short one-dimensional displays.
• Use conventional interaction elements. Make sure these are consistent throughout the user interface.
• Use graphics and labels that help people predict what will happen next in your UI design for elderly people.
• Avoid the use of “click here.” Instead, have the link include a description of what the user will find when the link is clicked on. For example instead of “Click here for more information on osteoarthritis” use “Osteoarthritis is the most common type of arthritis in older people”.
• Ensure that redundant links have the same labels.
• Do not underline anything that is not a link in your UI design for elderly people..
• Use different colors to distinguish between visited and unvisited links.
• Alt-text, hints and help bubbles should be in a readable font (see Vision section), be simply written, and displayed long enough for older adults to read them. Avoid covering up useful screen information with the hint or help bubble.
• Provide clear confirmation messages in any UI design for elderly people. .
• Each screen or page should be very distinguishable from others. Older people should be able to easily identify which screen or page is displayed and understand what they can do with it.
• Use the visual representation of the device to help users understand what areas they can interact with and the correct way to interact with them.
• Use minimalist design to prevent cognitive overload. Provide only those features in an app that the elderly user will need to accomplish the task. Avoid the use of irrelevant information on the screen.
• Use simplified “launchers” (for example the BIG Launcher in Android) to simplify user interfaces by removing unused device functionality.
• Consider the increased demand on spatial ability if left and right are used to represent up and down (or vice versa). Avoid this situation wherever possible.

To assist with forms and other modes of data entry:

• Group similar questions.
• Make required fields obvious.
• Give examples.
• Provide straight-forward and descriptive error messages that suggest a solution to the user.
• Provide logical and appropriate grouping of questions.
• Provide clear, easy to understand, questions
• Use checkboxes rather than drop-down or pull-down menus. If not possible, then use drop-down menus (menus that drop down when requested and stay open until the user closes it or chooses a menu item) rather than pull-down menus (menus that are pulled down and stay available as long as the user holds it open).
• Restrict the number of choices in lists. Where needed, break long lists into multiple shorter lists.
• Use checking and validation during completion of data entry. Avoid auto-correction.
• Provide step-by-step instructions and context sensitive help.
• Provide visual illustrations, pictures, and symbols to help explain ideas, events, and processes.
• Use words, not symbols, to indicate required fields.
• Provide text descriptions to identify required fields that were not completed.
• Provide a text description when user input falls outside the required format or values.
• Provide success feedback when data is submitted successfully.
• Provide wording that can be understood by people with lower than secondary education level reading ability.
• Provide links to definitions, glossaries, and explanations of abbreviations.
• Provide suggested correction text but avoid auto-correction.
• Provide the ability for the user to review and correct answers before submitting.
• Provide the ability to recover deleted information.
• Make small page changes obvious to accommodate ‘change blindness’ in older users.

Related Articles on Cognition:  Memory | Attention | Learning | Using Color When Designing Technology for Seniors