Variables in Research

Variables in Research

Definition of Variables

  • Variables refer to characteristics that have two or more mutually exclusive values or properties.

    • They are essential in research as they help in understanding relationships between various phenomena.

    • In contrast, constants are characteristics or concepts that have only a single, never-changing property or value, thus representing stable conditions in research.

Types of Variables (IDC)

Independent Variable (IV)

  • The independent variable is the condition or characteristic presumed to cause or influence the existence, non-existence, or change in certain phenomena.

  • It is the object of manipulation or control by the researcher in an attempt to determine its relationship to the observed phenomena.

  • Independent variables act as predictors of the dependent variable.

  • Example: Age (when bracketing demographic groups).

Types of Independent Variables (TA)

  1. Treatment Variables

    • Factors that the researcher manipulates and to which subjects are assigned.

    • Example: Different dosages of a medication given to experimental groups.

  2. Attribute Variables

    • Characteristics that cannot be changed by the researcher, such as age, sex, and intelligence level, but function as independent variables.

    • Example: Gender as a variable in studies examining behavioral differences.

Dependent Variable (DV)

  • The dependent variable is the condition or characteristic that is influenced by the independent variables.

  • It represents the outcomes, effects, or results which are the focus of the investigation.

  • Example: Patient recovery rates in a clinical trial.

Confounding Variables (CV)

  • Confounding variables may affect the measurement of the relationship between the independent and dependent variables.

  • The effects of confounding variables are sometimes mistaken for the effects of the independent variables, which can lead to incorrect conclusions.

  • These variables can affect both the independent and dependent variables.

  • These variables are not directly included in the study but must be controlled for to avoid skewed results.

Types of Confounding Variables (IE)

  1. Intervening Variable

    • An intervening variable cannot be controlled or measured directly but can have an important effect upon the outcome of measurement.

    • These are sometimes called modifying variables because they intervene between the cause and the effect, potentially altering the initial relationship.

    • They act by either strengthening, weakening, or eliminating the influence or effect of the independent variables on the dependent variables.

    • Example: Stress as an intervening variable between socioeconomic status and health outcomes.

  2. Extraneous Variable

    • Extraneous variables are not controlled or manipulated by the researcher but can significantly influence the result of a study.

    • Also known as exogenous variables, they intervene between the cause and the effect, introducing noise into the research results.

    • Example: Environmental factors that can affect a psychological study's outcomes, such as temperature or lighting conditions.