in a scientific experiment what is the function of a control group

Perhaps a review of the experimental method might be helpful.

An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.

A dependent variable is the response or measure of results.

Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.

The experimental group receives the independent variable.

The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.

Types of experiments

1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.

2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo are controlled by third party. This controls for experimenter bias and self-fulfilling prophecy, which means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.

As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.

The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.

The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.

If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.

I hope this helps a little more. Thanks for asking.

The function of a control group in a scientific experiment is to provide a baseline for comparison. It is a group in which the independent variable is not manipulated or altered. The purpose of having a control group is to ensure that any changes or effects observed in the experimental group can be attributed to the manipulation of the independent variable and not to any other factors. By comparing the control group with the experimental group(s), researchers can determine the specific impact of the independent variable being tested.

In a scientific experiment, a control group is a group that is used as a baseline or reference point to compare the results of the experimental group. The primary function of a control group is to provide a point of comparison to evaluate the effects of the independent variable(s) being tested.

To understand the function of a control group, it is important to understand some key concepts:

1. Independent variable: The variable that is deliberately changed or manipulated by the researcher in an experiment. It is the potential cause of any observed effects.
2. Dependent variable: The variable that is being measured or observed in response to the changes in the independent variable. It is the outcome or effect that is being studied.
3. Experimental group: The group or condition in an experiment that is exposed to the manipulation of the independent variable(s).
4. Control group: The group or condition in an experiment that serves as a comparison to the experimental group. It does not receive any treatment or manipulation of the independent variable(s).

The control group in an experiment is treated identically to the experimental group, except for the manipulation of the independent variable(s). By keeping all other conditions constant and withholding the experimental treatment, the control group allows researchers to isolate and identify the specific effects of the independent variable(s).

Comparing the results of the control group with the experimental group helps scientists determine whether any observed effects or changes are due to the controlled variables or the independent variable(s). It allows researchers to assess the validity and significance of their findings, ensuring that any observed effects are indeed a result of the independent variable(s) and not other factors. This comparison helps reduce bias and ensures that any conclusions drawn from the experiment are reliable and meaningful.

The control group is there to provide something to be compared to