Research Methods: Defining Variables

Variables

• Important to define both dependent (measured) and independent (manipulated) variables in research.
• Operational definitions ensure consistency in measurement or manipulation throughout the study.

Properties of Measurement

• Four key properties of measurement:
  • Identity: Different objects receive different scores.
  • Magnitude: Order reflects the variable's amount similarly.
  • Equal unit size: A difference of 1 is consistent across the scale.
  • Absolute zero: Score of zero signifies absence of the measured variable.

Scales of Measurement

• Four levels of measurement scales:
  • Nominal: Categorizes without numerical properties.
  • Ordinal: Ranks categories in a continuum.
  • Interval: Equal-sized intervals between numbers.
  • Ratio: Features order, equal units, and an absolute zero.

Discrete and Continuous Variables

• Discrete variables are whole number units or categories; cannot have decimal values (e.g., gender, political party).
• Continuous variables occur along a continuum and allow for fractional amounts (e.g., age, height, weight).

Types of Measures

• Four categories of data collection methods:
  • Self-report measures: Questionnaires or interviews reflecting behavior, thoughts, or feelings.
  • Tests: Assessment tools for individual differences in various content areas.
  • Behavioral measures: Observations and recordings of behavior.
  • Physical measures: Bodily activity measurements (e.g., pulse, blood pressure).

Nature of Data

• Data is dynamic and subject to change; reflects information relevant to specific times and contexts.
• Data can be corruptible and prone to inaccuracies from hearsay or bias.
• Knowledge derived from data is often expressed in soft statements indicating uncertainty.

Hierarchy of Information

• Structured as follows:
  • Theory: Abstract claims about the world.
  • Concepts: Building blocks of theory, can be abstract or concrete.
  • Indicators: Observable phenomena that suggest a concept's presence.
  • Variables: Measurable components of indicators.
  • Values: Actual measurement units for variables.

Theoretical Framework

• Theory formation includes complex claims developed through research and informal hypotheses.
• Concepts must be clearly defined for uniform understanding across different disciplines, particularly in social sciences.

Data Levels of Abstraction

• Research progresses from abstract theories to concrete data collection, ultimately returning to the theoretical level for conclusions.
• Research questions need to align with the appropriate measures and scales throughout the investigation process.

Primary and Secondary Data

• Primary data: First-hand reports collected directly by the investigator; closest proximity to truth.
  • Measurement: Numeric collections (e.g., temperature, sales).
  • Observation: Direct recordings of experiences.
  • Interrogation: Data from inquiries about beliefs and preferences.
  • Participation: Data from engaging in activities or experiments.
• Secondary data: Information collected by others for different purposes; used by researchers for new insights (e.g., census data).

This quiz focuses on the critical aspect of defining variables in research. It covers the essential concepts of operational definitions for both dependent and independent variables. Understanding these definitions is crucial for successful research projects.