Scientific control

A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.

Scientific controls are a part of the scientific method. In many scientific experiments, researchers use two or more samples to see if a difference is real. One sample, called the control group, is designed to eliminate the effects of all the variables except the one being tested. The other samples are experimental groups.

Purpose

The purpose of a scientific control is to provide an unbiased comparison. This allows scientists to eliminate the effects of variables that are not being tested. The control can be an object, an individual or a group that goes through the same steps as the experimental group except for the variable being tested.

Types of Controls

There are several types of scientific controls, each with a different purpose. These include:

• Negative controls: These are groups where no phenomenon is expected. They ensure that there is no effect when there should be no effect.
• Positive controls': These are groups where a phenomenon is expected. They ensure that there is an effect when there should be an effect.
• Statistical controls: These allow scientists to control for variables that might not be directly observable.

Examples

In drug testing, for example, a control group might be given a placebo while another group receives the experimental drug. The difference in outcomes between the control and experimental groups is used to measure the effectiveness of the drug.

See Also

• Controlled experiment
• Control group
• Dependent and independent variables
• Experimental design
• Observational study

Scientific control

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