This is the third edition of a successful book whose previous two editions were published in 1989, and 1994. It is a practical guide about health measurement scales called as well “latent outcomes”, such as cognitive abilities, attitudes, quality of life, etc, addressed to clinicians, users. and developers of health measurement scales.

In this third edition the authors have updated most of the chapters, mainly those related to cognitive requirements in answering questions, and include a more in depth chapter on item response theory.

The general content of the book follows the process of development and evaluation of health measurement scales. Chapters are devoted to the process of scale development, which includes basic concepts, how to devise and select items, and building scales. Chapters addressed to analyse attributes of the measures include reliability and validity, as well as measuring change. The chapter about ethical issues that researchers should take into account in their own fieldwork is also of valuable interest. Most chapters are accompanied by practical examples and a considerable number of tables and figures that make easy to understand and to interpret what authors want to explain. Appendices include commented bibliography and recommended reading, sources of developed scales, and a short introduction to exploratory and confirmatory factor analysis.

Through the whole book, authors also try to clarify their point of view on controversial concepts and present issues that are in the centre of the debate in scientific literature.

In summary, it is a highly recommended book for those not psychometric experts but users or developers of questionnaires in the area of health sciences. It is an essential reading for those who start working in this area. I am sure that it will be as successful as the previous two editions.