A Designer's Library

Most people are incapable of accurately assessing their own behaviors, especially when they are removed from the context of their activities.

As Donald Schön so aptly puts it, "design is a conversation with materials". This means that for a designer to craft an appropriate solution, he must understand the capabilities and limitations of the "materials" that will be used to construct the product, whether they be lines of code or extruded plastic.

No matter how skillful and creative the designer, if she does not have clear and detailed knowledge of the users she is designing for, the constraints of the problem, and the business or organizational goals that are driving design activities, she will have little chance of success.

Perpetual intermediates usually know that advanced features exist, even though they may not need them or know how to use them. But the knowledge that they are there is reassuring to the perpetual intermediate, convincing him that he made the right choice investing in this product.

Programmers create interactions suitable only for experts, while the marketers demand interactions suitable only for beginners, but [...] the largest, most stable, and most important group of users is the intermediate group.

[...] A well-balanced user interface [...] doesn't cater to the beginner or to the expert, but rather devotes the bulk of its efforts to satisfying the perpetual intermediate. At the same time, it provides mechanisms so that both of its smaller constituencies can be effective.

If we depend on words from the Mechanical Age, we will build software from the Mechanical Age. Better software is based on Information-Age thinking.

Design Principle: Significant change must be significantly better.

People don't find it difficult to adapt to newer, more useful representations of familiar systems.

When designers rely on Mechanical-Age representations to guide them, they are blinded to the far greater potential of the computer to provide sophisticated information management in a better, albeit different, way. The use of a Mechanical-Age representation in a user interface can operate as a metaphor that artificially constrains the design.

Design Principle: don't replicate Mechanical-Age artifacts in user interfaces without Information-Age enhancements.

As the history of the industrial revolution shows, the fruits of new technology can often only be expressed at first with the language of an earlier technology.

Any application that interacts with users in Boolean is doomed to suffer severe user interface problems. It is unreasonable to expect users to penetrate the confusion.

Just because a technique is well suited to solving a problem in software construction doesn't necessarily mean that it is well suited to be a mental model for the user.

If the represented model for software closely follows users' mental models, it eliminates needless complexity from the user interface by providing a cognitive framework that makes it evident to the user how his goals and needs can be met.

One of the most significant ways in which computers can assist human beings is by putting a simple face on complex processes and situations. As a result, user interfaces that are consistent with users' mental models are vastly superior to those that are merely reflections of the implementation model.