A friend of mine runs a university lab that studies users' eye movements as they read web pages. There is an actual science to measuring the way sites are viewed, where the eyes fall first, how they move across the screen, and how long they stay on specific page elements. This information gathered from these sessions is used to make recommendations to improve the overall user experience (UX), as well as help site designers get more mileage.
Eye movement-tracking may be an intricate solution for the UX challenge, but there are also simpler, and less snoopy, ways software developers and designers can keep tabs on how users are viewing interfaces. We're talking about employing key performance indicators (KPIs) to track users' experiences with software and services. As Armen Ghazarian shares in a recent post, KPIs can help software and service designers assess how well their interfaces are being received, whether they are creating any issues, and what design schemes are delivering the best results.
As with most things in technology, it's probably best if there are ways to capture feedback or flag issues in an automated fashion, versus finding out at a later date, through an email, phone call, or follow-up survey, that the interface has some ineffective aspects to it.
Ghazarian recommends five KPIs that would help provide insights as to the quality of the UX:
1. Task Success Rate (also known as the Task Completion Rate): This is the percentage of correctly completed tasks by users, Ghazarian explains. This metric is most effective for well-defined interfaces, such as registration or product order forms. Be sure to establish a basis of comparison with follow-up sessions, he adds. "This will give you an understanding of system's learnability."
2. Time on Task: This measures the time it takes "to complete the task, expressed in minutes and seconds," Ghazarian says. "This can be a useful metric for diagnosing problems."
3. Use of Search vs. Navigation: It can be surmised that extensive use of a site's search function suggests that the navigation is not so easy -- a red flag.
4. User Error Rate: Errors means user's mistake, Ghazarian says -- such as entering one's name in the address field of a form, or entering a credit-card number with the dashes when no dashes are permitted. This is a bellwether to the overall usability of the interface.
5. System Usability Scale (SUS): This is based on the pop-up surveys that users receive as they wrap up a session, asking for their perceptions of the site or service.