The art and science of scale development in health education research.

This conceptually-based article focuses on the value of the complementary or integrative use of qualitative and quantitative research methods in health education research. Specifically, the article describes a model for developing measurement scales using both qualitative and quantitative techniques. The qualitative methods of open-ended interviews and focus groups are used to develop questionnaire items. Quantitative methods (e.g. factor analysis) are used to test and refine questionnaire subscales. A discussion of reliability and scale validation is offered along with illustrative examples from recent health education research.