Can it work, does it work, is it worth it? 1 These three questions have been foremost in my mind throughout the revision of 'Introduction to Ergonomics'. In revising and updating the text, I have tried to attain three goals. First, to update the scientific content of the book to reflect the state of our knowledge at the beginning of the twenty-first century. Second, to maintain the book's essential character as a general introductory text that teaches the basic science that ergonomists use at work. Third, to add new material at the end of every chapter to answer the three questions above.
There is a great deal of evidence that ergonomics does work. It really does improve the interactions between people and machines and it really can make systems work better. How to demonstrate this has been one of the challenges in the process of revision. Several criteria have influenced the selection of supporting evidence. It would be ideal if evidence for the benefits of all of the diverse practices and subdisciplines of ergonomics came in the form of randomised controlled trials with double-blind application of treatments to satisfy even the most sceptical reviewer. This is not the case, and it never can be, so I have tried to present a variety of evidence that best exemplifies what each particular area has to offer.
The evidence comes in the form of field trials, field experiments, longitudinal studies and even a few laboratory experiments. Such a variety of research methods will never please everyone - what satisfies the university academic may seem dry and other-worldly to the production manager. Uncontrolled trials in real factories may not impress the academic, but practitioners may find therein much useful ammunition for arguing their cause.
Another theme that is pursued throughout the book is that engineering and design are increasingly driven by standards. Probably the best evidence that the value of ergonomics is now recognised is the publication of international standards for ergonomics. These standards are paving the way for a new, quantitative and much more precise form of practice. With this in mind, I have tried to inform the reader about these standards, wherever possible (with the rider that this is a textbook, not a design manual). The reader is encouraged to use these standards in practice and, with due deference to national bodies, the International Organization for Standardization (IOS) is recommended as the first port of call.
In keeping with these modern trends, some new essays and exercises have been added to encourage the learning of quantitative skills. Some of the older, perhaps
1Haynes. 1999. Can it work? Does it work? Is it worth it? British Medical Journal, 319 (Sep. 11): 652-653.