Summary
A group that does not receive the treatment, used as a baseline for comparison.
In depth
A negative control receives no treatment; a positive control gives a known effect to show the method works. Placebo controls and blinding reduce bias in clinical trials.
Controls show that the effect is due to the treatment. Blinding prevents expectation bias. Positive controls confirm the method works.
Remember: without a control, the result cannot be interpreted.
A control group is treated the same as the experimental group in every way except for the factor being tested, giving a baseline for comparison. A negative control should show no effect; a positive control uses a treatment known to produce an effect and shows that the method works.
In drug trials the control group receives a placebo, and participants are often randomly assigned and blinded (single or double) to prevent expectation effects. Without a control, changes might be due to time, handling or chance.
Example: when testing a new fertiliser, the control group of plants receives only water.
Frequently asked questions
What is Control Group?
A group that does not receive the treatment, used as a baseline for comparison.
Which area of biology covers Control Group, and how advanced is it?
Control Group is one of the 51 topics in Lab Methods & Biostatistics. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Experimental Design, Meta-Analysis, Variables.
Why does Control Group matter?
A control makes cause-and-effect conclusions possible.
Can you give an example of Control Group?
In a drug trial, one group receives a placebo.
What should I learn before Control Group?
Control Group is a Beginner topic, so no earlier topic is required. Other Beginner topics in Lab Methods & Biostatistics that pair well with it include Scientific Method, Hypothesis, Variables.
What topics are related to Control Group?
The closest topics to Control Group are Experimental Design, Meta-Analysis, Variables, Hypothesis. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Control Group?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Control Group. To practise the whole of Lab Methods & Biostatistics, use the Lab Methods & Biostatistics quiz.
How is Control Group different from Experimental Design?
Control Group: A group that does not receive the treatment, used as a baseline for comparison. Experimental Design: Randomisation, replication, blocking and blinding reduce bias and confounding. Read both side by side and note what each one explains.
How should I study Control Group step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Experimental Design and explain the difference aloud. Finally, take the Lab Methods & Biostatistics quiz and come back to this page for any question you miss.