"Count what is countable. Measure what is measureable. What is not measureable, make measureable." -- Galileo

Saturday, January 31, 2009

Usability for Seniors, Part 2

Last week I took a heuristic approach to usability by comparing general look-and-feel of various CMS homepages. For someone who is ostensibly promulgating the use of rigor in assessing IT solutions, that seems a bit shallow (although still useful--first impressions count a lot on the Web).

Continuing with my look into features that are making it hard for seniors to use websites, I took a moment to track down Jakob Neilson's Alertbox, a must-read for anyone interested in usability. Sure enough, he has a very recent posting on aging and usability.

The bottom line is that his research shows a 0.8%/year decline in performance. That is, each year you need almost a percent more time to complete a given online task. In the span of a career (40 years) one can expect to need 32% more time. (Not 38%-- Neilson states that time-on-task degradation is a not a compound interest phenomenon.)

Neilsen points out that by the time someone born in 1990 is at the end of their career, they'll have had a lifetime of web experience. So 0.8% is probably not going to hold over the long haul. He estimates for long-term (>10 years) purposes a 0.5% annual loss in performance just on the basis of general cognative and motor skill slow-down.

Neilson also states that far better than attacking that 0.8% per year issue is to just make your overall site highly usable. According to one of his surveys, a 10% increase in development for usability results in an astonishing 83% increase in conversions. (A conversion is having the site visitor actually do what you want them to do--probably download, install, and use Plone.)

Increasing usability and touting the fact that Plone is senior-friendly taps into the fastest-growing segment of Internet users. Admittedly, seniors are probably not web portal developers, but they could be, and more importantly, they are more likely to be managers with decision-making authority over IT investments.

To continue to quote Neilson:
"Because so many sites are hard for them to use, seniors will shower you with business if you're the honorable exception who acknowledges their special needs. (And, those needs aren't even that special -- it's much easier to make sites usable for seniors than for users with disabilities.)"
Now back to assessing CMS usability, normally, one would conduct a functional usability study by taking a representative sample of users and have them complete pre-selected tasks. Metrics would be success rate and time to completion. One key take-home lesson from this is that site designers should clearly identify critical user tasks and make absolutely sure that those tasks can be carried out quickly and easily.

Since I don't have the luxury of a pool of users to measure, I'll take a different approach: I'll take each of Neilson's top 10 mistakes in web design and score sites against them. Here's his top 10 list:
  1. Bad search
  2. PDF files for online reading
  3. Not changing the color of visited links
  4. Non-scannable text
  5. Fixed font size
  6. Page titles with low search engine visibility
  7. Anything that looks like an advertisement
  8. Violating design conventions
  9. Opening new browser windows
  10. Not answering users questions
I'd like to emphasize that:

"Web site success is significantly associated with Web site download delay (speed of access and display rate within the Web site), navigation (organization, arrangement, layout, and sequencing), content (amount and variety of product information), interactivity (customization and interactivity), and responsiveness (feedback options and FAQs)." ACM, 2002 (Alas, the full text version appears to be gone.)

For now, I'll stop drinking the Alertbox coolaid and settle down. I hope to return with some examples and numbers in my next installment.

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