A step-by-step approach to developing scales for survey research

While questionnaires and scales are some of the simplest methods of collecting data, their development requires a rigorous process. In recent years, several new questionnaires and scales have been developed. Although various papers have outlined how to develop questionnaires, their use in survey research, as well as how to ensure their validity and reliability, the actual development of scales - including the generation of items, scaling, the testing of validity and reliability, and refinement of the scale - is missing in the literature.

To outline a systematic and rigorous process for developing scales for survey research and to differentiate between three interchangeably used terms: scale, questionnaire and inventory.

Developing a valid and reliable scale is daunting because of the challenges associated with the conceptualisation, contextualisation and operationalisation of the phenomenon of interest. Researchers should use multiple approaches at each step of development to tackle these challenges.

This paper provides a step-by-step approach to developing scales by providing explicit instructions and practical examples. This six-step process can enable nurse researchers to develop a scale applicable to their study's intended population, which is also valid and reliable for measuring the phenomenon of interest.

Rigorous nursing research demands that instruments be valid and reliable measures. Systematic development of scales is key to ensuring that nurse researchers accurately measure abstract concepts when conducting surveys with a given population. This paper is a first step in addressing the gap in the methodological literature and will contribute to greater rigour in research.