UX Nuggets Thoughts and advice on usability and user experience
March 26, 2010 |
As user experience people, we often use the words that describe what we do casually or imprecisely. This confuses people who don't eat, sleep and breathe usability. I know people who say “I do usability” or “I need some usability testing.” What they’re really saying is “I specialize in making things more usable” and “I have to figure out what’s wrong with this application and fix it so my customers can complete their orders.”
Sometimes people talk about usability as a process – doing “usability testing.” Sometimes it is described as an attribute of an artifact – “that application is really usable.” Both are reasonable, but the difference can be confusing.
We can often say that one system has greater usability than another system based on measurements of user performance measures. In aggregate, these measures constitute an overall usability attribute that describes how easily people can use the system to achieve a goal. Usability as defined by NIST and others consists of three measurable components:
For instance, we can measure how many transactions happen in a given period of time or the number of errors that are made. Ultimately, the results of these measurements are interactions between design factors and properties of the user. Measurement leads to diagnosis; diagnosis leads to interventions that, in turn, we hope, increase the usability of the system.
On the other hand, we also use the term “usability” as an adjective to describe a process, such as “usability engineering” or “usability testing.” Having a usable system is the end point in the usability engineering process. It is more of a journey, and relies on understanding the science base of human factors and engineering psychology, user interface standards and guidelines, and research tools from behavioral sciences.
Knowing what needs to be changed does not mean we know how to change it to improve the design. For that we need designers skilled in the art and science of user experience design. Highly usable systems derive from a usability process that relies on:
Usability is not a difficult concept, but sometimes we make it confusing. Perhaps we need better terms.
Robert Schumacher, Executive Vice President, has more than 25 years of professional experience in corporate and academic environments with expertise in areas such as global user research, health information technology and contact center applications. He holds a PhD in Cognitive and Experimental Psychology from the University of Illinois at Urbana-Champaign.