By: Margaret Tassin, CFSP, CDC
VP, Programs
BFMA is extremely fortunate to have a long-standing relationship with one of the most respected authorities on user interface design, Mr. Bill Galitz. He has recently published the third edition of "The Essential Guide to User Interface Design" (2007, Wiley Publishing Company, Indianapolis, Indiana, 857 pages.
Wilbert (Bill) O. Galitz is an internationally respected consultant, author, and instructor with a long and illustrious career in human factors and user-interface design. For many years he conducted a screen design course for BFMA. Click here for a complete biography.
The article below is the fourth in a series and is derived from the author’s most recent book, "The Essential Guide to User Interface Design". You can order this book from BFMA.
Bill discusses website development and standards for seniors.
Website Use For Seniors
The invasiveness of the Web has greatly expanded the range of computer users. Computers are no longer the domains of the young and middle-aged only. Older people are now a significant force in Internet use and the Internet is quickly graying. AARP says that more than 40 million adults over 50 are online in the United States. The Center for Digital Future at the USC Annenberg School says that the percentage of Internet use by older users is:
• Age 45–55 86%
• Age 56–65 75%
• Age 66 + 41%
Age can have a profound effect on computer, system, and Web usage. Older people are all subject to the unavoidable physical degradations that occur in vision, hearing, cognitive processing, and manual dexterity.
Vision
The eye is a sense organ that begins to diminish in effectiveness at an early age, as anyone over 40 can attest. The eye begins its aging process in our early thirties, the amount of light able to pass through the retina beginning to lessen. At 40 the process accelerates, and by age 50 most people need 50 percent more light to read by than they did when they were in their twenties. Failing to be able to read a menu in a dimly lit restaurant is often the first time we become aware of this problem.
Also occurring is a reduced lens elasticity preventing focusing close to the eyes. The dreaded bifocal lens becomes a necessity. One’s field of vision is also reduced, constricting the edges of what can be seen, and reduced retinal efficiency occurs hindering adapting to glare and changing light conditions. As a result of these changes, older adults read prose text in smaller type fonts more slowly than younger adults (Charness and Dijkstra, 1999). To aid older users:
• For text to be read or scanned, use:
• 12 to 14 point sans serif font (Helvetica, Arial).
• Black text on a white background.
• Left justification.
• Increased spacing (leading) between lines.
• Sentence style mixed-case letters rather than all capital letters.
• Appropriate large headings in a 14 to 16 sans serif font.
• Use few colors, and avoid using blue and green tones.
Hearing
As people age, they require louder sounds to hear, a noticeable attribute in almost any everyday activity. Hearing comfort levels, in decibels, for sounds at various age levels are (Cohen (1994):
Age Sound level in dB
25 57
45 65
65 74
85 85
To aid older users:
• Provide captions or transcripts of important audio content.
• Provide an option to display a visual cue for all audio alerts.
• Provide an option to adjust the volume.
• Use audio as an enhancing design characteristic.
Cognitive Processing
Brain processing also appears to slow with age. Working memory, attention capacity, and visual search appear to be degraded. Older users, a study found, had more problems with Web searches that required three or more mouse clicks, and they searched less efficiently than younger users, requiring 81% more moves (Mead et al., 1997). Memory limitations seemed to be the cause of most of these problems. Older people also had a harder time adjusting to computer jargon and recovering from errors (Dulude, 2002). To aid older users:
• Concentrate important information at the top of pages.
• Put most links in a bulleted, not tightly clustered, list.
• Provide a clear differentiation between visited and non-visited links.
Manual Dexterity
As people age, their manual dexterity diminishes. Typing and mouse movements become slower. The ability to operate some input devices decreases. A double-click on a mouse, for example, is increasingly more difficult to perform as dexterity declines. Morris and Brown (1994) also found, in a task requiring speaking into a computer, that older users had an average speaking rate 14% slower than younger users. To aid older users:
• Provide large targets to make selection easier.
• To reduce the number of selections or clicks:
• Do not require double-clicks.
• Do not use pull-down menus.
• Do not have a deep page hierarchy.
• Avoid the need to scroll to find information.
Applying these guidelines would also, of course, benefit all users of Websites. As always, usability testing should be performed to ensure an effective system for seniors.
References
Charness, N. and Dijkstra, K. (1999). “Age, luminance, and print legibility in homes, offices, and public places.” Human Factors, 41 (2)173–193.
Cohen, S. (1994). “Most comfortable listening level as a function of age,” Ergonomics, 37 (7)1269–1274.
Dulude, L. (2002). “Automated telephone answering systems and aging.” Behavior and Information Technology, 21 (3), 171-184.
Mead, S.E., Spaulding, R.A., Sit, B.M., and Walker, N. (1997). “Effects of age and training on World Wide Web navigation strategies.” Proceedings of the Human Factor and Ergonomics Society 41st Annual Meeting, 152–156.
Morris, R. J., and Brown, W. S. (1994), “Age-related differences in speech variability among women.” Journal of Communication Disorders. 17, 469.
Recent Comments