Interaction design

Everyone has the experience of not fully understanding a product? A parking meter, television or mobile phone. It happens to everyone, but why don’t we fully understand products at first glance? One possible explanation is the different ‘mental’ models of designers and users.

Donald Norman introduced the term ‘conceptual model’ in the design world, but Philip Johnson-Laird’s was the first on who studied this subject. He proposes that people construct a mental model after reading a text. Especially if the text is ambiguous these mental models can be quite different from person to person, because the text can be interpreted in different ways.

Norman used the theory of ‘mental models’ in psychology for product design and called them ‘conceptual models’. A conceptual model is the mental model people have of the ’system’. All that users interaction with builds this model, including the physical properties, documentation, icons and instructions.

How designers communicate through design

Designers seldom speak to their users when their product is introduced to the market. They cannot sit on the couch next to the user to explain how the product works and what the user should do if they make a mistake. Instead they have to communicate through the design of the product. The design should have enough use cues to inform the user. To be successful in this communication it is essential that the mental model of the ‘designer’ is the same as the ‘user’. Naturally this is not the case since designers think about products on a different level and are far more experienced in product use.

That is why designers have to keep in contact with their potential users and check if they got it right. A variety of methods exist to bridge this difference in both mental models. If designers succeed in creating products with the same ‘mental models’ as their users there is a high chance that users are satisfied with their product. On the long run this will create costumer loyalty and increase revenue.

What if the communication fails?

The communication of the product can fail because the mental model of the designer and user are not similar or when the designer fails to transform the mental model into the right product design.

When designer don’t speak at all with their users there is a high probability they will end up with a product that does not match with the ‘mental model’ of the user and designer. The designer thinks he has created a product that is easy to use and improves people’s life. In reality users get frustrated or uncomfortable because they do not fully understand the product’s use cues. In other words; the product fails to communicate how it should be used.

Let’s assume that the designer is of good will and has tried dig into his users. He knows how the think and what they want from the new product. Understanding your users is one thing, transforming this into the right product is another step. When failure occurs the result could be similar to the situation above. Having user tests along the development of the product can reduce the uncertainty of failing in the communication. Regular tests can confirm if you are on the right track or if the design has to be changed.

Principles for good communication in design

Besides testing your product with users regularly several principles can be applied during the design of the product.

• A good conceptual model, consistent use of presenting operations and their results.
• At all time the product should give feedback about the result after an action.
• Good visibility should inform users about the options they have
• Natural mapping shows relationships and takes advantage of physical analogies and cultural standards.

In upcoming articles we will discuss these four principles in more detail.