2. Measurement of Variables
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 definition does 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