The Design of Everyday Things

Two of the most important characteristics of good design are discoverability and understanding.

Good conceptual models are the key to understandable, enjoyable products: good communication is the key to good conceptual models.

Design is concerned with how things work, how they are controlled, and the nature of the interaction between people and technology.

Affordances determine what actions are possible. Signifiers communicate where the action should take place. We need both.

industrial designers emphasizing form and material, interactive designers emphasizing understandability and usability, and experience designers emphasizing the emotional impact.

So we must design our machines on the assumption that people will make errors.

Discoverability: Is it possible to even figure out what actions are possible and where and how to perform them? Understanding: What does it all mean? How is the product supposed to be used? What do all the different controls and settings mean?

The ones we are concerned with here are simpler: they reside in the minds of the people who are using the product, so they are also “mental models.” Mental models, as the name implies, are the conceptual models in people’s minds that represent their understanding of how things work. Different people may hold different mental models of the same item

Two of the most important characteristics of good design are discoverability and understanding.