Design to simplify

Good design of object must help:

• Discovery: Design should enable users to anticipate possible actions, their timing, and where to perform them.
• Understanding: Users should comprehend the purpose of an object, its functions, and how to effectively utilize its commands and settings.

Good design clarifies how objects work and facilitates interaction between people and technology.

Operator errors due to design can lead to frustration or, in complex systems, serious consequences.

The logical user

• Designers often expect users to be as logical and attentive as they are.
• However, designing for users as they are, assuming mistakes, is crucial.

Fundamental principles of interaction

• Experiences determine how interactions are remembered, approach to a new interaction and expectations from future interaction, so they must be pleasant.
• Lack of understanding leads to frustration, while understanding generates control and satisfaction.

Basic concepts

Affordance and signifiers

Affordance in objects are the perceived interactive properties of the objects showing how to use the object.

When affordance is not perceivable, design must signal its existence: this is the signifier.