the ? is the part of an experiment that is not being tested and is being used for comparison.

CONTROL?

This might help you understand the experimental method better.

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. Thanks for asking.

It is the CONTROL.

The part of an experiment that is not being tested and is being used for comparison is called the control group. The control group provides a baseline against which the experimental group can be compared. It helps to assess the effects of the independent variable by providing a standard of comparison.

To determine the control group in an experiment, follow these steps:

1. Identify the independent variable: This is the variable that you are intentionally changing or manipulating in the experiment.

2. Determine the dependent variable: This is the variable that you are measuring or observing to see how it is affected by the independent variable.

3. Designate the control group: The control group should be a group or condition in the experiment where the independent variable is not applied or manipulated. It should be kept under normal or standard conditions.

For example, let's say you are conducting an experiment to test the effectiveness of a new medication on a certain disease. In this case, the control group would consist of a group of individuals who are given a placebo (a harmless substance with no therapeutic effect) instead of the actual medication. By comparing the results of the control group with the experimental group (who receive the actual medication), you can determine the effectiveness of the medication.

Remember, having a control group in an experiment is essential to ensure accurate and reliable results by accounting for any potential confounding variables and providing a reference point for comparison.