What Is the Experimental Group?

In a psychology experiment, the experimental group (or experimental condition) refers to the group of participants who are exposed to the independent variable. These participants receive or are exposed to the treatment variable. The data that is collected is then compared to the data from the control group, which did not receive the experimental treatment.

By doing this, researchers are able to see if the independent variable had any impact on the behavior of the participants.


  • "To assess the impact of the independent variable, we must have at least two different treatment conditions so that we can compare the effect of different values of the independent variable. At times, one condition is an experimental condition and the other is a control condition. In the experimental condition, we apply a particular value of our independent variable to the subjects and measure the dependent variable. The subjects in an experimental condition are called an experimental group."
    (Myers & Hansen, 2012)
  • "In the ideal experiment, the professor wouldn't want to use established groups. Instead, she would make up the groups herself by assigning subjects to the experimental or control group on a random (chance) basis. The assignment into one group or the other would be made on the basis of something like a coin flip. This procedure would help her guard against stacking one group or the other with particular types of people, which would influence the results. Using random assignment, each subject has an equal chance to be assigned to the experimental group."
    (Robbins, 2003)

    More Psychology Definitions: The Psychology Dictionary


    Myers, A. & Hansen, C. (2012) Experimental psychology. Belmont, CA: Cengage Learning.

    Robbins, P. R. (2003). Understanding psychology. Portland, Maine: Walch Publishers.

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