1. Measurement of Variables
Chapter 8
Measurement of Variables

2. Research Design: Measurement and Measures

3. How Variables are Measured
Objective data
Eg weight, absenteeism, temperature
Use appropriate measuring instruments
Subjective data
Eg. feelings, attitudes, perceptions
Difficult to measure
Abstract concepts to be broken down into obsevable behavior
Operationalise the concept

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

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

6. 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?

7. Common Mistakes with Operational Definitions
Excluding some of the important dimensions and elements
Failure to recognise or conceptualise important dimensions
Including certain irrelevant features mistakenly thought to be relevant.
E.g Success in performance cannot be a dimension in achievement motivation.

8. 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.

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

10. SCALES
A scale is a tool or mechanism by which individuals are distinguished as to how they differ from one another on variables of interest to our study.

11. Measurement Scales Nominal Scale Ordinal Scale Interval Scale
Ratio Scale

12. Nominal Scale

13. Nominal Scales
Nominal scale allows the researcher to assign subjects to certain categories or groups.
Example.
Please indicate your current martial status.
__Married __ Single __ Single, never married __ Widowed
The categories' should be
-Mutually Exclusive
- Collectively Exhaustive

14. Nominal Scale
Splits data into mutually exclusive and collectively exhaustive categories
Zip code of residence
Employment status
Marital status
Gender
Race
Religion
Ethnicity

15. Ordinal Scale

16. Ordinal Scales
Ordinal scales categorize the variables in such a way as to denote the difference among the various categories, it also rank-orders the categories in meaningful ways.
Example.

17. Interval Scales
Interval scales demonstrate the absolute differences between each scale point
Example.
How likely are you to recommend the Santa Fe Grill to a friend?
Definitely will not Definitely will

18. Interval Data

19. Ratio Scales
Ratio scales allow for the identification of absolute differences between each scale point, and absolute comparisons between raw responses
Example 1.
Please circle the number of children under 18 years of age currently living in your household.
(if more than 7, please specify ___.)

20. Ratio Data Market share Sales (units and dollars) Income
Number of salespersons per territory
Number of full-time employed members of household
Number of children in household