The best kind of design isn't necessarily an object, a space, or a structure: it's a process- dynamic and adaptable.

Also note that invariably when we design something that can be used by those with disabilities, we often make it better for everyone

What makes something simple or complex? It's not the number of dials or controls or how many features it has: It is whether the person using the device has a good conceptual model of how it operates.

When you have trouble with things—whether it's figuring out whether to push or pull a door or the arbitrary vagaries of the modern computer and electronics industries—it's not your fault. Don't blame yourself: blame the designer.

The world is complex, and so too must be the activities that we perform. But that doesn't mean that we must live in continual frustration. No. The whole point of human-centered design is to tame complexity, to turn what would appear to be a complicated tool into one that fits the task, that is understandable, usable, enjoyable.

Design is really an act of communication, which means having a deep understanding of the person with whom the designer is communicating.

The designer shouldn't think of a simple dichotomy between errors and correct behavior; rather, the entire interaction should be treated as a cooperative endeavor between person and machine, one in which misconceptions can arise on either side.