Introduction

Usability is of vital importance for user satisfaction. In fact, it is of decisive importance that users actually reach their goals with the user session or they will simply go away. Unsatisfied.

Qualitative user testing usually expose bad designs and usability problems, but they do not give us statistically significant figures of the degree of usability. Furthermore, quantitative user surveys are not suitable to measure usability since users tend to be very bad at analysing their own behaviour.

Why measure the degree of usability on web sites?

We can set up goals and track them. There are two types of goals:

  1. Find out how well you are doing on a regular basis. Are you on the right track?
  2. Assess our competitive position, are you better or worse than your competitors?

But how do you measure usability?

  1. Identify critical user task that are important for your websites' success.
  2. Set up goals for these tasks
  3. Find 40 representative users.
  4. Start measure usability for your website (and competitors). Start with: percent of tasks completed, ratio of successes to failures, time to complete a task and satisfaction with functions and features.
  5. Calculate a usability index for each web site.
  6. Correct design flaws.
  7. Do this every year or often.