An extraneous variable is any variable that is not being investigated but has the potential to affect the dependent variable in a research study
. These variables can be uncontrolled and may lead to inaccurate conclusions about the relationship between the independent and dependent variables
. Extraneous variables can introduce various research biases, such as selection bias
. There are four main types of extraneous variables
:
- Demand characteristics : Environmental cues that encourage participants to conform to researchers' expectations
- Experimenter effects : Unintentional actions by researchers that influence study outcomes
- Situational variables : Factors, conditions, or characteristics related to the external environment that can influence a situation's behavior, decision-making, or outcome
- Confounding variables : Variables that affect both the independent and dependent variables and can cause a spurious association between them
Extraneous variables should be controlled where possible, as they might provide alternative explanations for the effects observed in a study
. Researchers can minimize the impact of extraneous variables by designing well-controlled experiments and considering various factors that could affect the dependent variable
