Difference between Controlled Group and Controlled Variable in an Experiment with example

Control Group

A good control group is similar to the experimental group in all way except for the difference in the experimental condition (that is the independent variable that the researcher changes).

Let us discuss these terms with a simple experiment

Suppose a researcher has developed a bio-fertilizer and wants to test its effect on plant growth. Therefore the experiment is “Effect of Bio-fertilizer ‘x’ in plant growth"

See the Figure 1 and 2 for understanding these terms in research

The variable is the factor you might measure in an experiment

A variable is any factor, trait, or condition that can have different values, change in variable influences the outcome of experimental research

Three types of variables:

      1. Independent variable: The variable that researcher changes or the researcher think it will affect the dependent variable

      2. Dependent variable: The variable that is affected by change  in independent variable

   3. Controlled variable: The variable that is kept constant or same throughout the experiment.

Control group	Controlled variable
It is the group that you are not conducting experiment (Figure 1) Know more: Experimental group vs control group	All the variable that are kept constant or same throughout the experiment. (Figure 2) Know more: Difference between Independent, Dependent and controlled variable
The researcher is not changing the independent variable	The researcher has kept this variable constant or given a standard value
Helps to compare experimental result with non experimental natural result (control group). It increases the reliability and validity of experimental results	Essential to get an unbiased result on the effect of independent variable studied by the researcher