For instance, in an experiment on plants, some plants may be subjected to variables - different fertilisers, soil, temperature, daylight, diseases, etc. While other plants would be kept separate as a control. The control plants would not be subjected to any variables or experiments. The control plants would be used to compare the growth and the effects on the plants that were subjected to the variables.
the "control"
An experiment in which all variables stay the same is called a "controlled experiment".
Variables.
The factors which you change (vary) are called variables.
Variables
variables
These "variables" are called independent variables or constant variables meaning that they are capable of being changed by the experimenter but are intentionally held the same through each individual experiment.
things in an experiment that stay the same are called constants.
the dependant variable
Variables that do not change in an experiment are independent variables.
Variables that do not change in an experiment are independent variables.
Independent and Dependent Variables
the only variables in an experiment are the independent variables [the thing in an experiment your going to change. and the dependent variables [the thing in an experiment your going to measure.