Controlled experiment

Definition

A controlled experiment is a scientific investigation where one or more variables are manipulated to determine their effect on a dependent variable, while keeping other variables constant. This approach allows researchers to establish causal relationships by eliminating the influence of external factors, ensuring that any observed changes can be attributed directly to the manipulated variable. The design is crucial in hypothesis testing and laboratory settings as it provides a clear framework for drawing valid conclusions.

5 Must Know Facts For Your Next Test

1. Controlled experiments are designed to isolate the effects of the independent variable by controlling for other variables, allowing for clearer conclusions about cause and effect.
2. These experiments often use a control group that does not receive the treatment, providing a baseline for comparison against the experimental group.
3. Replicability is a key feature of controlled experiments; they should yield consistent results when repeated under the same conditions.
4. In laboratory settings, controlled experiments allow researchers to manipulate environmental factors, leading to more precise measurements and stronger conclusions.
5. Ethical considerations can limit the use of controlled experiments, especially in social sciences or medical research where manipulation of certain variables may not be permissible.

Review Questions

• How does a controlled experiment help in establishing causal relationships between variables?
  • A controlled experiment helps establish causal relationships by systematically manipulating one or more independent variables while keeping all other conditions constant. This design allows researchers to observe any changes in the dependent variable and attribute those changes directly to the manipulated factors. By eliminating external influences and having a control group for comparison, the results provide strong evidence of cause and effect.
• What role does randomization play in enhancing the validity of a controlled experiment?
  • Randomization plays a critical role in enhancing the validity of a controlled experiment by ensuring that subjects are assigned to different groups in an unbiased manner. This process minimizes potential confounding variables and helps create comparable groups. As a result, any observed differences in outcomes can be more confidently attributed to the treatment or manipulation rather than pre-existing differences among participants.
• Evaluate the ethical implications of conducting controlled experiments in social sciences and how these implications might affect research outcomes.
  • Conducting controlled experiments in social sciences often raises ethical implications regarding manipulation of variables that may affect participants' well-being. Researchers must consider informed consent, potential harm, and the impact of their findings on communities. Ethical constraints may limit what can be tested or how experiments are designed, potentially affecting the breadth of research outcomes. Balancing rigorous experimental design with ethical responsibilities is essential to ensure that research contributes positively while maintaining participant rights.

Related terms

Independent Variable: The variable that is intentionally changed or manipulated in an experiment to observe its effect on the dependent variable.

Dependent Variable: The variable that is measured or observed in an experiment, which is expected to change as a result of manipulating the independent variable.

Randomization: The process of randomly assigning subjects to different treatment groups in an experiment to reduce bias and ensure that each group is comparable.