Full Blog: Design of Everyday Things

Reference Information

Title: Design of Everyday Things

Author: Donald Norman

Editor: Basic Books, 2002

Summary
This book discussed good and bad design principles and presented real-world examples to support the claims. Donald Norman emphasizes throughout the book the strong need for visibility, conceptual models, mappings, and feedback. Visibility is necessary in order to indicate how a system should be operated. Conceptual models are the visible structure of a system, including affordances, constraints, and mappings that allow the user to predict the consequences of a particular action within a system. Feedback lets the user know what has actually occurred within the system as the result of some action.

The author also discussed how people think about and act with systems, including the tendency of a person to blame themselves for an error that occurred due to faulty design. In addition to this, people tend to find incorrect ways to explain things due to coincidence. Because of this, it may be unclear that something is wrong with the design of a system.

Different types of knowledge exist, including knowledge contained in the head (a person's memory) and knowledge contained in the world (environmental reminders such as sticky notes and natural constraints). People rely on signals, such as natural constraints and affordances, from objects in order to know how they should be used. Constraints include physical constraints, semantic constraints (that rely on the situation), cultural constraints, and logical constraints (a logical relationship between spatial or functional layout). Design can be improved by applying these constraints and affordances in order to eliminate common errors.

Errors were discussed in detail, explaining the difference between slips, that result for similarities between actions, and mistakes, that result from making wrong choices. The reasoning behind errors is presented due to models of human thought, including rationality and the connectionist approach (neural networks). Forcing functions of physical constraint work as possible error preventions.

The author argues strongly for designer awareness to design systems that are easy to use and fairly self-explanatory.

Discussion
This book seems like it would be very useful to apply to the design of systems. The author mentioned many good points, and provided good examples to illustrate each, such as the function of a typewriter and the use doors and elevators.

An example of bad design involving a door.

While this book did present many useful ideas, it was rather wordy and repetitive. The author repeated the same ideas in many of the chapters. In particular, the first and last chapters seemed to be almost the same. There were many examples presented, but the one I liked the least was an example of a door with a lock at the top designed to keep handicapped children inside of a building. The author praised this as an example of good design, but all I could see it being is a danger in an emergency situation.

For future projects, I will definitely keep many of these design principles in mind. In particular, the four main ideas of  visibility, conceptual models, mappings, and feedback could be very useful to incorporate within systems.