On a Winter’s Night

Abstract

In part two of this book we have examined a variety of everyday devices to see the many characteristics of machines—such as concurrency, hierarchy, relationship between mode and reference values, default setting—that directly affect user interaction. We also considered several important principles of human interaction such as population stereotypes, generalizations, and consistency. In part three of this book, we will see how these characteristics of machines and principles of user interaction play out in much more complicated systems such as cruise controls of a car, medical equipment, and aircraft automation.

The elementary unit of information—is a difference which make a difference.

—Gregory Bateson, Steps to an Ecology of Mind, Part V, chapter 5