Because if you change more than one variable at a time, you can't tell which is affecting the results.
If you test only one variable then you know that the difference in the experimental and control setup is that one independent variable. If you test more than one you will not know which one made the difference.
This variable is chosen by the research team according to the experiment project.
Independent variable : )
The independent variable.
The independent variable.
An experiment in which only one variable changes is called an "controlled experiment" or "single-variable experiment." In this type of experiment, the researcher manipulates one variable (independent variable) while keeping all other variables constant to determine its effect on the outcome (dependent variable). This approach helps to isolate the impact of that single variable on the results.
A variable test?
it is a fair test
this is an experiment that only one varible is manipulated at a time
It would not be a fair test if there were 2 or 3
The one variable in an experiment that is changed to test a hypothesis.
Manipulated variable