What’s the advantage of my ratings? In short, business-aligned usability ratings help me communicate the actual business impacts of the issues we identify during usability testing. They include information about how a user experience issue can affect an organization’s brand equity and revenue.
Before I present these ratings, let’s first review some definitions of usability and user experience, as well as some common classifications of usability or user experience issues.
Let’s go to the more authoritative sources first. The ISO standard for usability (ISO 9241-11) defines usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.”
Another popular definition is Jakob Nielsen’s conceptualization of usability as a “quality metric” with five components:
- learnability—How easy is it for users to accomplish basic tasks the first time they encounter a product or service?
- efficiency—Once users have learned a product or service, how quickly can they perform tasks using it?
- memorability—When users return to a product or service after a period of not using it, how easily can they re-establish proficiency?
- errors—How many errors do users make, how severe are those errors, and how easily can they recover from the errors?
- satisfaction—How pleasant is it to use a product or service?
In my own practice, I’ve typically defined usability in a broad context. Here’s my working definition:
Your intended users can accomplish what they’re trying to do with your product or service.
However, as you’ll soon see, I’ve oriented my ratings of usability issues with a tighter focus on business problems and their solutions.
Defining User Experience
ISO 9241-210 defines user experience as “a person’s perceptions and responses that result from the use or anticipated use of a product, system, or service.” Other definitions follow this perception/emotion-centric view, as we can see in Wikipedia’s definition: “User experience is about how a person feels about using a system.” Others adhere to a component-based definition of user experience—for example, Peter Morville’s user experience honeycomb, which comprises usefulness, usability, desirability, value, accessibility, credibility, and findability.
I’ve always liked Morville’s definition of user experience best, but found even it somewhat lacking because—like other definitions I’ve run across—it didn’t seem to put enough focus on the business outcomes. So rather than simply creating and advocating for yet another definition of user experience, I began evaluating usability or user experience issue ratings with a focus on an organization’s business objectives.