"Task success is up substantially compared with usability statistics from 2004. Bad information architecture causes most of the remaining user failures.
"If the customer can't find the product, the customer can't buy it" was one of the first slogans I devised about Web usability. This truism remains in force today, because getting to the right page within a website or intranet is the inevitable prerequisite to getting anything done.
(When users actually do find what they want, content usability obviously becomes crucial: people have to understand and like the information at their destination. Still, getting there is the vital first step.)
Web Usability Metrics: 2004 vs. 2009
In 2004, we analyzed the causes of the user failures we observed when user testing 25 websites for the 1st edition of our Fundamental Guidelines for Web Usability course. (We've since updated the seminar several times — adding video clips and statistics from newer studies — but, true to the name, most of the 2004 guidelines were in fact fundamental enough to remain in force today.)
This year, we conducted a similar broad-ranging study of 24 websites for our new 2-day seminar on information architecture (IA). Although there are many other courses on this topic, ours is based on empirical studies of what actually works for real users. Our study's main goal was to develop usability guidelines and get video clips for our presentation, but we also analyzed users' task outcomes, applying the classifications scheme we developed in 2004.
(For more on how to classify usability problems and rate their severity, see our book Prioritizing Web Usability.)
The happiest finding was that, averaged across the broad range of sites we tested, the success rate had improved nicely:
* 66% in 2004
* 81% in 2009
Clearly, Web usability has taken hold in recent years, and Internet managers are getting more reluctant to launch "cool sites" that waste company money and fail to support the business.
Our new study's findings further support task success stats from other recent research, in which we updated previous studies in 3 key areas:
* Site maps: success rates improved somewhat, from 69% to 71% in 7 years.
* "About Us" information: success rates improved moderately, from 70% to 79% in 5 years.
* Store finders and locators: success rates improved considerably, from 63% to 96% in 7 years.
The amount of the increase obviously varies — from fairly small for site maps, which have recently become a bit of a stepchild for Web designers, to immense for store finders, which are a ca-ching of a money-maker (after all, if customers can't find a shop, they can't go shopping).
Our consulting projects show the same broad pattern: websites are definitely easier to use now than they used to be. This is also true for intranets — in fact, they've actually improved more than websites because they started out with particularly miserable usability.
IA Problems Still Prevent Task Completion
Although usability has improved overall, IA is becoming a sore thumb that's preventing websites from meeting their business goals. The following pie charts show the outcome of user task attempts in our two broad website studies:" (Continued via (Jakob Nielsen's Alertbox) [Usability Resources]