Which of the following is a defining characteristic of an experiment in psychological research?

• A. Observation of participants in their natural environment without intervention
• B. Manipulation of an independent variable to observe its effect on a dependent variable
• C. Collection of self-reported data through surveys and questionnaires
• D. Analysis of existing records and archival data

Answer: (B)

Verified step by step guidance

1. Understand that an experiment in psychological research is designed to test cause-and-effect relationships between variables.
2. Identify the key components of an experiment: the independent variable (IV), which is manipulated, and the dependent variable (DV), which is measured to observe the effect of the manipulation.
3. Recognize that manipulation of the independent variable means the researcher actively changes or controls this variable to see how it influences the dependent variable.
4. Contrast this with other research methods such as naturalistic observation (no intervention), surveys (self-reported data), and archival research (analysis of existing data), which do not involve manipulation of variables.
5. Conclude that the defining characteristic of an experiment is the deliberate manipulation of the independent variable to observe its effect on the dependent variable.