One of the key things about designing user interfaces is to realise that you are constantly working to achieve a compromise…a compromise between many forces that are trying to tug the ui down one design path or another. These forces may be related to personal taste, emotions, business rules, familiarity, and other fuzzy vagaries, but to be honest, although they play a part, they are not nearly as important as the user’s experience of the interface in driving the direction and the detail of the design.

There is simply one thing the user wants to be able to do:

  1. Get the job done…
  2. without wasting time…
  3. and enjoy doing it

OK – so we made that three things really. Why? Well, because each of those three things are compromised at the expense of the others. Let’s look at them in more detail:

1) Get the job done: The design in question needs to allow the user to achieve their goal(s) in an efficient manner with the minimum of fuss. Typically, however, there are likely to be many possible goals which any one of a huge number of users might want to achieve at any one time, and they might want to do them very often or not very often at all. So now we need to cater for all users to achieve all goals…which leads us to:

2) without wasting time: How can we cater for many users and many goals and not have a complex interface that means some users waste time looking for what they want and wondering how to reach their goal. Answer: Yep –  it’s a compromise. On the one hand we want the design to allow user A to hit the button that says ‘do my task’ and on the other, we need to allow users B to ZZ to hit the button that says ‘no do mine’. We can’t have an interface cram-packed with a sea of buttons, although many try! So we design the interface to be on average as efficient as possible for the greatest number of users to achieve the most common goals. That is why we need to understand the users: who they are, how experienced they are, what they know, what they want, how they do it. All in order to reach the best compromise we can…which leads us to:

3) and enjoy doing it: So we get a compromise between getting the job done and not wasting time but does the user get any satisfaction out of it – and we don’t mean by playing Bruch’s Violin Concerto No 1 in the background, although that would be lovely. This depends on introducing a little psychology into the user experince. Did the user get annoyed with anything? Did the user have to hang around waiting? Did the user wonder what was happening? Were they informed of progress? Did any part of the task feel repetitive? Did lots of decisions have to be made? Was the interface nicely designed? Was it too wordy? Were the icons not clear enough? Would they use it again – or go for the competition? Hundreds of little things can help the user to progress forward without having to think any more than absolutely necessary. Novice users and expert users need to have different ways of achieving the same tasks. The design needs to incorporate learnability and to appear smart. Help needs to be available. It should not just meet but exceed expectations. This all makes the design more complex as a whole, but whilst taking care not to unnecessarily detract from letting the user get a job done and without wasting time doing it.

So, usability is about achieving a compromise between these three things. (Yes, it’s also about much more than that, but that’s not the point here).

Usability is a balance between providing an intuitive, efficient and satisfying design:

Defining usability

Defining usability