The foreword to the book “Apple Human Interface Guidelines,” pp. xi-xii.

From its inception, Apple Computer has had a vision: to bring the power and versatility of computers to ordinary people. The Desktop Interface, introduced with the Lisa® and further developed on the Macintosh™, represents a quantum leap toward that goal. This book presents the rationale behind the Apple Desktop Interface and provides guidelines for software developers who want their products to be consistent with the Desktop Interface. Various Apple® hardware systems can accommodate this interface in varying degrees. So far, the Macintosh is the most mature implementation of the interface, and we rely on it for the examples in this book. You’ll understand this book better if you’ve used one or two standard Macintosh applications and read a Macintosh owner’s guide.

The best time to familiarize yourself with the Desktop Interface is before beginning to design an application. Good application design happens when the developer has absorbed the spirit as well as the details of the Desktop Interface. Human interface design should come first, not last.

An interface is not merely a visual display – in fact, it’s possible to have an interface with no visual display at all. A human interface is the sum of all communication between the computer and the user. It’s what presents information to the user and accepts information from the user. It’s what actually puts the computer’s power into the user’s hands.

One of the great advantages of the Desktop Interface is its consistency: a user who learns one application already knows a good deal about other applications. For example, Command-X and Command-V mean Cut and Paste in all standard applications; selecting a block of text and choosing Italic from the Style menu has the same effect in any application. This consistency makes it easier for a user to learn new applications; it also makes it less likely that a user who follows habits learned from one application will make a disastrous mistake when using a different one.

The Desktop Interface comprises features that are generally applicable to a variety of applications, but not all of the features are found in every application. In fact, some features are hypothetical because they anticipate future needs, and may not be found in any current applications.

This book will be most useful if you already have some experience with a desktop-based Finder program and with the concepts of pointing, clicking, and dragging with the mouse. You should also be familiar with some application programs that use windows, pull-down menus, and a mouse – preferably one each of a word processor, a spreadsheet or data base, and a graphics application.

Although you can find examples of most of the features described in this book by looking at existing applications, no one program has fully implemented these guidelines, and perhaps none ever will. Taken together, the Finder (version 5.5), MacWrite® (version 4.5), MacPaint® (version 1.5), and MacDraw® (version 1.9) come close to containing the full set of features as described here. Because these applications evolved in parallel with the Human Interface Guidelines, none of them is a perfect implementation of the guidelines: where the application differs from the guidelines, follow the guidelines. While there are some very good applications that deviate in significant respects from these guidelines, emulate those applications only with good reason. If you do deviate from the guidelines, make sure that the user will not get into trouble by following habits learned from standard applications: a pathological example would be to change the meaning of Command-S from Save to Shut Down-without-saving.

These guidelines are not the last word on this subject, just as the Desktop Interface is not the last interface. New features will be found that will make the interface more effective, and eventually new interfaces will appear. For now, these guidelines represent the interface that Apple recommends for all computers in the Apple II and Macintosh product lines.

You’ll find detailed implementation specifications in the technical documentation for the particular Apple computer for which you’re developing software. If you haven’t already done so, you can become a registered or certified developer, which makes you eligible for additional information. Contact Apple Developer Relations for details.

This book is a joint effort of two groups at Apple: the Human Interface Group and the Technical Publications Group.