Chapter 2. Principles of Measurement Scales
Published Online: 8 MAR 2002
DOI: 10.1002/0470846283.ch2
Copyright © 2000 John Wiley & Sons, Ltd
Book Title
Quality of Life: Assessment, Analysis and Interpretation
Additional Information
How to Cite
Fayers, P. M. and Machin, D. (2002) Principles of Measurement Scales, in Quality of Life: Assessment, Analysis and Interpretation, John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/0470846283.ch2
Publication History
- Published Online: 8 MAR 2002
- Published Print: 18 APR 2000
ISBN Information
Print ISBN: 9780471968610
Online ISBN: 9780470846285
- Summary
- Chapter
Keywords:
- constructs;
- latent variables;
- indicator variables;
- causal variables;
- global questions;
- multi-item questionnaires;
- multi-item scales;
- psychometrics;
- item response;
- clinimetric scales
Summary
The principle methods for developing and validating new questionnaires are introduced, and the different approaches are described. These range from simple global questions to detailed psychometric and clinimetric methods. We review traditional psychometric techniques including summated scales and factor analysis models, as well as psychometric methods that place emphasis upon probabilistic item response models. Whereas psychometric methods lead to scales for QoL that are based upon items reflecting patients' level of QoL, the clinimetric approach makes use of composite scales that may include symptoms and side-effects of treatment.