Variables: Types and Operational Definitions

Variables: Types and their Operational Definitions
Unit III: Problem identification formulation of research objectives and hypothesis (as part of M.Optom Curriculum of Pokhara University, Nepal)

1. Variables: Types and Operational Definitions Rabindra Adhikary [email protected] M. Optom , 1 st Batch (2019) Tilganga Institute of Ophthalmology Pokhara University Facilitator: Mohan Krishna Shrestha , TIO Date: 13 June 2019 Main Topic: Unit III: Problem identification formulation of research objectives and hypothesis (as part of M.Optom Curriculum of Pokhara University, Nepal)

2. variables Learning Objectives: Define and explain variables Define and explain the operational definitions of variables with example

3. What is a variable Image, perception or a concept Which is measurable (Measurability) Whose value is variable (Variability) Key to Quantitative research Provides rational ground (after analysis) to come to a conclusion

4. Kerlinger : ‘ A variable is a property that takes on different values. Putting it redundantly , a variable is something that varies ... A variable is a symbol to which numerals or values are attached ’ (1986)

5. Black and Champion define a variable as ‘rational units of analysis that can assume any one of a number of designated sets of values’ ( 1976)

6. Concepts vs Variable

7. Types of Variables Generally, variables are classified on three basis: Causal Relationship Study design Unit of measurement

8. Casual Relationship Change variable (Independent) Brings about change in the phenomenon or situation under observation Outcome variable (Dependent) Effects or consequences of change variables Influencing variable (Extraneous) Influences or affects the link between cause-and-effect variables Linking Variable (Intervening) Necessary to complete the relationship between cause and effect variables

9. Intervening variables, also called confounding variables because it links the independent and independent variables What was the actual cause? Necessary to establish the link between dependent and independent variables

10. Types of variables in causal relationship

11. Example

12. Variables from the viewpoint of study design Active Variables Can be controlled, changed or manipulated Contents, structure, testability Attribute variables Can’t be manipulated, changed or controlled Age, weight, gender, etc

13. From the viewpoint of unit of measurement Categorical variables Qualitative Nominal and ordinal scales Continuous variables Quantitative Interval and ratio scales

14. Video 1

15. Video 2

16. Continuous? These variables can have any numeric value Weight of a person : 60kg, 61.7kg, 62.4kg Height of a person: 5.5”, 6.2”, 7.1”

17. Operational Definitions A statement that specifies the procedures (the operations) used to measure the variable operational definition of a variable is the specific way in which it is measured in that study

18. Example Intelligence Use 5 min Execute task

19. ?? Physical Attractiveness Depression (ask questions to the audience to set the operational definitions of these variables)

20. Comparison

21. Thank You