Which of the following is a major problem in causal research?

• A. Random sampling guarantees that all biases are eliminated.
• B. Descriptive statistics are always sufficient for establishing causality.
• C. Confounding variables can threaten the validity of causal conclusions.
• D. Correlation automatically implies causation.

Answer: (C)

Verified step by step guidance

1. Understand that causal research aims to determine whether one variable directly affects another, establishing cause-and-effect relationships.
2. Recognize that confounding variables are extraneous factors that can influence both the independent and dependent variables, potentially misleading the interpretation of causality.
3. Note that random sampling helps in generalizing results but does not eliminate all biases, especially those related to confounding variables.
4. Understand that descriptive statistics summarize data but do not establish causal relationships; inferential methods and experimental controls are needed for causality.
5. Remember that correlation between two variables does not imply that one causes the other; other factors, including confounders, may explain the relationship.