Variables: Types and Operational Definitions
Download as PPTX, PDF3 likes2,821 views
The document discusses the concept of variables in research, outlining their definitions, types, and operational definitions within the framework of quantitative research. It categorizes variables based on causal relationships, study design, and measurement units, providing examples for clarity. The document emphasizes the importance of operational definitions for measuring variables effectively in research studies.
Variables: Types and Operational Definitions
- 1. Variables: Types and Operational Definitions Rabindra Adhikary [email protected] M. Optom, 1st 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)
- 7. Types of Variables • Generally, variables are classified on three basis: – Causal Relationship – Study design – Unit of measurement
- 9. 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
- 10. • 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
- 11. Types of variables in causal relationship
- 12. Example
- 13. 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
- 14. From the viewpoint of unit of measurement • Categorical variables – Qualitative – Nominal and ordinal scales • Continuous variables – Quantitative – Interval and ratio scales
- 15. Video 1
- 16. Video 2
- 17. 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”
- 18. 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
- 19. Example • Intelligence – Use 5 min – Execute task
- 20. ?? • Physical Attractiveness • Depression (ask questions to the audience to set the operational definitions of these variables)
- 22. Comparison
- 23. Thank You