E-commerce sites in the United Kingdom risk losing more than £300 million in sales each year because of “invisible errors” that bedevil consumers but can’t be detected by web analytics, according to a new study from SciVisum, a UK-based web site testing specialist.
SciVisum says these errors typically impact only a small percentage of users at any time. A problem that affects only one in 100 users, for example, is often not reproducible by a site’s technology team and frequently goes unresolved, says Deri Jones, CEO.
One-third of consumer site visits tested by SciVisum had more than 3% error rates, while more than 10% experienced extreme inconsistencies in delivery speed.
Among the intermittent and hard-to-spot errors found by SciVisum were:
• Page-not-delivered errors. Because the page is not delivered, there is no log of the error in the web analytics.
• Jump back. The user is forced back several pages. The new page itself is a valid page, so no errors are logged in analytics or tech logging.
• Page content incomplete. Web analytics log only that a page was delivered, not whether it showed the user what they expected.
• Shopping basket errors. A basket is empty after adding items. This category of problem typically is not detected in server or analytic logs.
• Session swap, where two users see each others’ online sessions. This category of problem typically isn’t detected in server or analytic logs.
SciVisum also found massive inconsistencies in content delivery speeds. More than 30% of visits experienced performance varying by more than 200%, with one in 10 experiencing performances varying more than 300%, based on data averaged over a seven-day period.
Web site performance was commonly worst between 8 p.m. and 10 p.m., coinciding with peak traffic levels, SciVisum found.
“As a specialist web tester, we’ve come into contact with invisible errors for some time now, but it was only when conducting this research that the extent of the problem became so apparent,” Jones says. “The UK’s online landscape is plagued by these errors and as users continue to become web savvy and increasing numbers of people encounter them, they won’t remain invisible for long.”
For the study, SciVisum tested 52 multi-page user visits for 40 online organizations between April and September 2007. SciVisum’s testing takes a mystery-shopper approach, visiting the site and attempting to make a user visit every 5 minutes throughout the day.