The single factor tested in an experiment is - The variable
Variable is an element or factor that is meant to vary or change in an experiment. Variables are used in Algebra where they are used as a defining variable or 'x' to describe any number.
The variables can be - independent variables, dependent variables, constant variables etc.
I know this because 8 is the only number they give you the other numbers they dont suply. Ps dont use my spelling and you might want to come up with a better answer. good luck
