What term describes a research design in which one or more variables are systematically manipulated to observe effects on an outcome variable?

What term describes a research design in which one or more variables are systematically manipulated to observe effects on an outcome variable?

• A. Correlational research
• B. Experimental research
• C. Cross-sectional
• D. Descriptive statistics

Answer: (B)

Manipulating the independent variable and observing changes in the dependent variable defines experimental research. In this design, the researcher deliberately changes one or more factors (the IV) in a systematic way and measures the resulting effect on an outcome (the DV). This controlled manipulation, often paired with random assignment to conditions and a comparison group, helps isolate the causal impact of the IV by keeping other potential influences constant. Because the researcher controls the timing and level of the manipulation and uses a control condition, experimental designs allow stronger inferences about cause and effect than designs that only observe relationships. In contrast, correlational research studies the relationship between variables without manipulating them, so it cannot establish causation. Cross-sectional designs collect data at a single point in time rather than testing how changes in one variable cause changes in another. Descriptive statistics focus on summarizing and describing data, not on testing causal effects.

Manipulating the independent variable and observing changes in the dependent variable defines experimental research. In this design, the researcher deliberately changes one or more factors (the IV) in a systematic way and measures the resulting effect on an outcome (the DV). This controlled manipulation, often paired with random assignment to conditions and a comparison group, helps isolate the causal impact of the IV by keeping other potential influences constant. Because the researcher controls the timing and level of the manipulation and uses a control condition, experimental designs allow stronger inferences about cause and effect than designs that only observe relationships.

In contrast, correlational research studies the relationship between variables without manipulating them, so it cannot establish causation. Cross-sectional designs collect data at a single point in time rather than testing how changes in one variable cause changes in another. Descriptive statistics focus on summarizing and describing data, not on testing causal effects.