Measuring Usability: Web Analytics
If your company has the luxury of having its own usability staff or the budget to invest in complex laboratory analyses, more power to you. Unfortunately, most of us aren't in that position and for someone like myself, who works to put usability principles into practice for small and medium-sized businesses, we often have to get creative and make do with what's available.So, how can a smaller website or one with a limited budget assess usability? I'm going to be exploring that question over the next few User Effect entries, with the goal of compiling those entries into a white paper on the subject.
For the first installment, I'd like to explore how you can get clues about usability from your existing traffic logs and web analytics. Although analytics have been around almost as long as websites, they've matured a lot in the last few years, and we're still just beginning to tap into their value.
It's All Relative
Whenever you're taking a fresh look at your web analytics, it's important to keep in mind that there are seldom "right" answers. Getting caught up in absolutes and what any given number should be is a recipe for insanity. Websites vary wildly, and you need to have a good understanding of your own site's baselines. For any given statistic, focus on improvement and gradually sorting out the story behind the number.
Statistic: Pages/Visit
One of your first clues to your website's usability is whether or not your visitors stick around long enough to see what you have to offer. Web surfers are notoriously impatient, and this is probably the biggest battle of website usability. Tracking the average number of pages per visit is a good starting point to understanding whether or not your visitors are sticking around. Again, don't focus too much on what a "good" number is. If you've got a blog where most of the visitors hit the home-page, getting them to 2-3 pages/visit could be fantastic. If you've got an e-commerce site where the product ordering page is 5 layers deep, a 2-3 page/visit average is probably a bad sign.
Statistic: Time on Site
Similarly, the average time each visitor spends on your site is, generally speaking, negatively correlated with frustration (as the statisticians would say). The more time people spend on your site, the better, especially if you're trying to sell a product directly.
Statistic: Bounce Rate
Your "bounce rate" is an indicator of how many people leave immediately after hitting your site (or a particular page on your site). It should come as no surprise that you want to drive the bounce rate down. It's important to note that many factors can conspire to inflate the bounce rate. If a lot of people hit your site and immediately leave, you may have usability issues, but you may also have marketing, search engine results, etc. that aren't well matched to your site (i.e. people arriving at your site aren't finding what they expect). In a loose sense, I consider this an aspect of usability, but unraveling it can be tricky.
Tool: Exit Pages
This is less of a statistic and more of a tool for finding your trouble spots, but most analytics packages will tell you where your visitors are exiting. Specifically, look for points in your process that seem like unnatural exit points. It's not uncommon for people to exit at major entry points (like your home-page), but if a large number of users are dropping out at the second page of your shopping cart, for example, you may have a usability problem. Finding and fixing these problem points can have a major impact on your bottom line.
Don't Panic
If you haven't looked at your analytics for a while or haven't looked at some of these particular numbers before, don't panic. Website visitors are a fickle bunch, and your bounce rate and other numbers may make your heart skip a beat or two the first time you see them. Focus on the big picture and work towards improvement. Website usability is, ideally, an ongoing process of optimization, and today's numbers are just a benchmark for figuring out where you'd like to be tomorrow.
