Author: Donald A. Norman
‘I am famous for doors that are difficult to open, light switches that make no sense, shower controls that are unfathomable’ (page vii). The author introduces his book with this statement, a reflection of his reputation in the field of equipment design. He says ‘far too many items in the world are designed, constructed, and foisted on us with no understanding -or even care- for how we will use them’. The book shows how design strongly influences function, and stresses the hazards of poorly designed equipment. The author employs his knowledge of cognitive science to demonstrate how badly conceived equipment result in misuse, errors and learned helplessness (page 42). The author says ‘…most accidents are attributed to human error, but in almost all cases the human error was the direct result of poor design’ (page viii).
The book initially describes the components of good design. The basic element is what he calls natural design. The object itself should send out natural signals which are then naturally interpreted (page 4). A good equipment therefore ‘…requires no diagrams, no labels, and no instructions’ (page 78). A key feature of natural design is the equipment’s affordance; the appearance of a device should provide the ‘critical clues required for its proper operation’ (page x); in other words ‘the device must explain itself‘ (page xi). He says ‘when instructions have to be pasted on something…it is badly designed’ (page xii). Similarly, ‘…when simple things need pictures, labels, or instructions, the design has failed’ (page 9).
Another core feature of good design the author explores is the constraint (page 62). This means the design should minimise how much knowledge is required to operate the equipment. The visibility of the equipment is another important characteristic of well-designed equipment; ‘…the correct parts must be visible, and they must convey the correct message’ (page 4). The book explores these features in detail in chapter 4.
Why are some equipment poorly designed in the first place? The main reason suggested by the book is that designers often consider aesthetics over usability (page 151). The end-user is often not sufficiently considered, and is rarely involved in the design or purchase of the equipment (page 78). Designers also frequently fall into the trap of creeping featurism, the tendency to keep on adding features to a single equipment (page 172).
How can the problem of poor design be redressed? The author devotes a substantial part of the book to this question. The primary solution he offers is to consider the end-user when designing any equipment. He says that ‘…the needs and requirements of people ought to be driving much of the work throughout the entire process’ (page xiv). This will result in user-friendly equipment. Another consideration, stressed throughout the book, is to design for safety. To do this, the author says designers should learn about the causes of error, and aim to minimise mistakes, or make them easily detectable and reversible (page 131). He discusses the different types of human error (slips and mistakes), and how to avert them. He also lists the seven action stages of design which should be considered (page 52). The last chapter gives a helpful guide to user-centered design.
The author discussing good design
There is nothing like an expert writing about his specialism and making it accessible to those not actively involved in the field. The author applies his knowledge of cognitive psychology to good effect, deftly explaining the principles of design and, importantly, linking these to safety. His conversational style makes this a very enjoyable read. The principles the book elaborates are universal and timeless. There are a few technical issues which the reader may skip without affecting their understanding of the book.Many of the examples the author uses are everyday things, but the lessons apply to all equipment. The cover is well-designed and thought out.
Doctors need to know the dangers of badly designed equipment, and the solutions to these risks. This book excellently addresses these issues and I strongly recommend it.