Understanding Measurement Scales and Operational Definitions in Research

2. Chapter 8 Measurement of Variables

3. Chapter Objectives • Operationally define (or operationalise) concepts • Explain the characteristics and power of the four types of measurement scale — nominal, ordinal, interval and ratio

4. Research Design: Measurement and Measures

5. How Variables are Measured • Objective data • Eg weight, absenteeism, temperature • Use appropriate measuring instruments • Subjective data • Eg feelings, attitudes, perceptions • Operationalise the concept

6. Operational Definition Is a statement of the specific dimensions and elements through which a concept will become measurable.

7. Dimensions (D) and Elements (E) of the Concept (C) ‘Achievement Motivation’

8. Examples of Questions to Tap the level of ‘Achievement Motivation’ • To what extent would you say you push yourself to get the job done on time? • How frequently do you think of your work when you are at home? • How much do you concentrate on achieving your goals? • How annoyed do you get when you make mistakes?

9. Common Mistakes with Operational Definitions • Excluding some of the important dimensions and elements • Arising from failure to recognise or conceptualise them • Including certain irrelevant features mistakenly thought to be relevant.

10. What an Operational Definition is Not • An operational definitiondoes not consist of delineating the reasons, antecedents, consequences or correlates of the concept • Rather, it describes its observable characteristics in order to be able to measure the concept.

11. Dimensions (D) and Elements (E) of the Concept (C) ‘Learning’

12. Measurement Scales • Nominal Scale • Ordinal Scale • Interval Scale • Ratio Scale

13. Nominal Scale

14. Nominal Scale • Splits data into mutually exclusive and collectively exhaustive categories • Eg, men, women

15. Ordinal Scale