Review by: Dreier, Matthias (2004-09-07)

Jakob Nielsen is currently the best-known usability expert and this book is the main reason for his fame. The book consists of ten chapters covering numerous usability methods and design principles. It also comprises a 100-page appendix including exercises and lists of important monographs, papers, conferences, and journals.

The executive summary starts with usability anecdotes and focuses on cost savings and discount usability. Key usability concepts are expressed in rather simplified slogans, e. g. “the user is always right” and “designers are not users.”

A more thorough definition of usability is given in chapter two. Usability is seen as part of the overall system acceptability and has five components: Learnability, efficiency, memorability, error handling, and user satisfaction. Usability has to take into account not only the system itself but also the user’s experience, domain knowledge, and work environment.

Chapter three illustrates the history of user interfaces and usability aspects related to these interfaces. Nielsen outlines long-term trends in usability and predicts that usability is not likely to improve very much. The selection of the appropriate user interface type for a given task is illustrated using Ben Shneiderman’s taxonomy of interaction styles.

The usability engineering lifecycle is presented in chapter four. The focus is on early usability efforts, iterative design and participatory approaches. Methods like task analysis, prototyping and competitive analysis are presented. Usability metrics and financial impact analysis are treated as well.

Ten basic usability heuristics are introduced in chapter five. These principles include feedback, shortcuts, good error messages, and most important of all: consistency. Heuristic evaluation is described as one method of assessing usability in a cost-effective way.

User testing being the “most fundamental usability method” is presented in chapter six. Nielsen explains in detail how to plan a test, how many test users might be appropriate, and what methods are suitable for given test tasks. He then describes the stages of a test and the equipment needed.

Chapter seven presents usability assessment methods beyond testing. Advantages and disadvantages of questionnaires and interviews are compared. Other methods more useful when designing a completely new interface or after the system has been released are described, too.

User interface standards are described in chapter eight. Again, consistency is mentioned as the most important principle. Difficulties in designing and implementing standards are discussed. Standards themselves often have usability problems, i. e. they are formulated to fuzzy or to low-level. Interface designers prefer example interfaces to written explanations.

Chapter nine addresses international user interfaces. Problems arise not only from translation but also from different character sets in foreign countries. Along with foreign characters, difficulties with sorting, capitalisation and highlighting occur. Iconographic interfaces do not fully resolve these problems because icons and colour coding are not universal. Nielsen recommends conducting at least one usability test with a foreign user.

Future developments are outlined in chapter ten. Nielsen is not too optimistic about some “magic” technology dramatically decreasing usability problems in the future. Speech recognition has been said to replace traditional input devices for many years. Expert systems and “intelligent” help systems promised to reduce usability problems. Much research has been conducted in the field of formal methods but they did not live up to their promise.

“Usability Engineering” is a comprehensive introduction to usability methods and interface design. The book is full of practical advice ready to be applied in real-world settings. The executive summary should be read by anyone who is involved in interface design. Developers find useful design principles in chapter five. Usability laboratory staff will appreciate chapters six and seven. The usability engineering lifecycle presented in chapter four includes all stages of interface development from task analysis and prototyping to evaluating the final product. The book is certainly a must-read for practitioners and researchers in the field, however not everyone needs to read the whole book. The chapter on international user interfaces only addresses people who are actually involved in designing multi-lingual interfaces. Equally, the extensive appendix only appeals to those who are indeed interested in background information, e. g. students in the field of human factors. Chapter three on the history of user interfaces is a little bit dated. Interfaces have changed a lot since 1993: graphical user interfaces have largely replaced command-line interfaces and the World Wide Web has leveraged the interface style known as hyper-text. Searching has become more important than navigating. Nevertheless, this book contains usability methods and design principles not likely to be out-dated in the next ten years.