Controlled experiment意思
"Controlled experiment" is a scientific term that refers to a type of experiment designed to test the effect of a single variable on a phenomenon under study, while keeping all other variables constant. The purpose of a controlled experiment is to establish cause-and-effect relationships between the independent variable (the one being manipulated by the experimenter) and the dependent variable (the outcome that is measured).
In a controlled experiment, the experimental group (the one exposed to the independent variable) is compared to a control group, which is not exposed to the independent variable. The control group serves as a baseline or a point of comparison to determine the effect of the independent variable on the dependent variable.
Here are the key features of a controlled experiment:
-
Manipulation of the Independent Variable: The experimenter manipulates one variable to determine its effect on the outcome.
-
Control of Confounding Variables: All other variables that could influence the outcome are kept constant or controlled across both the experimental and control groups. This helps to isolate the effect of the independent variable.
-
Randomization: Subjects or samples are often randomly assigned to either the experimental or control group to ensure that both groups are representative of the population and to minimize any systematic biases.
-
Replication: The experiment is typically replicated multiple times to ensure the reliability and validity of the results.
-
Blinding: Sometimes, to minimize bias, the experiment is conducted in such a way that neither the subjects nor the researchers know to which group a particular subject belongs (single-blind), or neither the subjects nor the researchers know the group assignments (double-blind).
Controlled experiments are widely used in various fields of science, including biology, chemistry, physics, psychology, sociology, and economics, to name a few. They are considered a powerful tool for establishing causality in scientific research.