What is Usability? - Definition & Tools

Instructor: David Gloag

David has over 40 years of industry experience in software development and information technology and a bachelor of computer science

We have a lot of choices in our lives. In this lesson, we'll take a look at one method of evaluation, usability, what it is, its attributes, and the best tool for determining it. At the end, you should have a good understanding of this fundamental concept.

The Woes of Choice

We live in a world that offers us a significant number of choices on a wide variety of things. There are choices for the movies we would like to see and the theatres we can see them in. There are choices for the type and color of the vehicles we drive. And there are choices for the size, color, and weight of the clothes we wear. At times, it seems like there are too many choices. In a reality with this abundance of choice, how do we decide? Sometimes, we simply must have it. But the rest of the time, we go through an evaluation process that determines the advantages and disadvantages of the item. That process involves usability.

What is Usability?

Usability is the method or process we use to determine how easy something is to identify, comprehend, and ultimately use. We measure or rate usability by considering five major attributes, or factors. They are as follows:

  • Learnability - describes how quickly something can be understood and put to use.
  • Efficiency - describes how quickly something can be used once understanding is achieved.
  • Memorability - describes how easily something can be put down, then picked up and used after some time has passed.
  • Errors - describes how often errors are created during use, and how quickly the user can recover from them.
  • Satisfaction - describes how pleasing something is to use.

Taken together, these factors represent a complete overview of the usability of an object. Think about any object that you use in your life. What is it about that object that warrants a place in your home, your purse, or your pocket? Why have you chosen that specific one over the other choices? Likely, one or more of the attributes mentioned were part of the decision.

As an example, consider the vehicle you drive. Why did you select it over the other possibilities? Could you quickly learn the basic operation of things like the radio or navigation system? Once you learned the basics of the radio, could you put them to use quickly? When you went to look at other vehicles, could you come back to the first and immediately continue where you let off? Did you make mistakes when trying to find the wiper controls or headlights? Could you easily recover it you did? And overall, was the vehicle pleasing to drive?

Chances are one or more of these questions came into play while deciding. In other words, usability helped you arrive at the conclusion that the vehicle you chose was the right one for you.

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