Ability to use is not simplicity to use

At conferences or meetings, a lot of people ask me the difference I make between usability and behavioural sciences. An answer to this question is indeed key to learn this profession and start off on the right basis. 

Usability means “ability to use”. This can be understood in two different ways.

  1. For a human being, usability is a person’s capability of using an object in order to complete a task. 
  2. From the object’s standpoint, usability is the capability of an object to be used by a human being in order to complete a task. 

Experience teaches us that whoever can use an object and that whatever object can be used by a person. It is a question of time: the time needed to complete the task. The motivation of the user also plays a role. 

Remote control simplicity

An example to illustrate this:

Products to be tested: two remote controls

User scenario: “I want to watch the Amélie Poulain DVD after a hard day’s work”. 

  1. Person’s standpoint: the person can use the two objects to watch the film.
  2. Object’s standpoint: the two objects can be used by the person to watch his movie. 

The two objects have the capacity to be used in order to meet the objective – to watch the movie – , so they are both usable. 

There are however important differences between the two objects. In the first case, the functionalities have been reduced to the basics, the icons have simple and well-known semantics, the visual elements reduce eye movements and have been grouped together so that the eye can see them without moving off centre. 

All criteria linked to the functioning of the brain and the eyes don’t make the remote control at the left more usable. But, this device will be more usable for people who just want to use the basic functions of their remote control.

The perception of an object’s simplicity is based on laws that rule our behaviour. 

Leonardo da Vinci describes simplicity as follows: “Simplicity is the ultimate sophistication”. 

My 15 years of experience have taught me that the ultimate sophistication is based on a thorough understanding of human behaviour, of the tools allowing to predict this behaviour and a scientific methodology that avoids the subjective opinions of consultants. 

Behavioural sciences will allow us to build an optimum object in function of the behaviour it wants to generate for a specific task, to be performed by a well-defined target group. The result: the target group will find the object easy to use.