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Social Sci LibreTexts

Variables, etc

  • Page ID
  • Variables

      • Defining, Measuring, & Manipulating

        • IVs

        • DVs

          • Levels?

        • Confounding variables

      • Reliability

      • Validity

    Operational definition of a variable

    • A definition of a variable in terms of operations/activities that a research uses to measure/manipulate it

    • Gives a variable a concrete definition so you can actually use it in an experiment, this allows the researcher to maintain consistency.

    • All variables involved in a study should be operationalized

      • Dependent Variables (what is measured)

      • Independent Variables (what is manipulated)

    Levels of Measurement

    • Identity

      • Measurement in which different objects receive different scores

    • Magnitude / ordinality

      • Measurement in which the ordering of numbers reflects the ordering of variables

    • Equal Unit Size

      • A difference of 1 is the same amount throughout the entire scale

        • EX “the height difference between two people who are 64 inches tall and 65 inches tall is the same difference between those who are 72 inches tall and 73 inches tall”

    • Absolute Zero

      • Assigning a score of zero indicates an absence of the variable being measured

    Scales of Measurement

    • Nominal

    • Ordinal

    • Interval

    • Ratio

    Discrete Variables

    Continuous Variables

    Types of Measures

    • Self-report

    • Tests

    • Behavioral

    • Physical


    • Types of Reliability

      • test/retest

      • Alternate-forms

      • Split-half

      • Interrater

    • How to Measure Reliability


    • Content

    • Criterion

    • Construct

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