Which of the following statements about extraneous variables is not accurate?

• A. Extraneous variables are always intentionally manipulated by the researcher.
• B. Researchers should attempt to control extraneous variables to increase the internal validity of a study.
• C. Random assignment can help minimize the impact of extraneous variables on experimental outcomes.
• D. Extraneous variables can introduce unwanted variability into an experiment, potentially confounding the results.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of extraneous variables. These are variables other than the independent variable that might affect the dependent variable in an experiment, but they are not the focus of the study.
2. Step 2: Recognize that extraneous variables are not intentionally manipulated by the researcher; instead, they are factors that researchers try to control or account for to prevent them from influencing the results.
3. Step 3: Review why controlling extraneous variables is important: it helps increase the internal validity of the study by reducing confounding influences that could bias the results.
4. Step 4: Understand that random assignment is a technique used to distribute extraneous variables evenly across experimental groups, minimizing their impact on the outcome.
5. Step 5: Identify the inaccurate statement by comparing each option to the correct understanding of extraneous variables, focusing on whether the statement correctly reflects their nature and role in research.