∞ generated and posted on 2016.08.21 ∞
Conditions for which a positive result intentionally does not occur, that is, a negative result instead occurs.
The negative control typically is what one compares the outcome of an experiment to. That is, a positive result, which is a change in the dependent variable, is something that is different from what one sees with the negative control whereas a negative result is the same as that seen with the negative control.
Negative controls can also show that the experimental conditions are capable of producing a negative result. For example, if one observes what one perceives to be a change in dependent variables, then even if one can compare that result quantitatively or qualitatively with initial conditions, to gain a sense of how much change occurred, one still will not have a means of knowing whether the positive experimental results could possibly have not have occurred. If you don't know that something could not have occurred, then how can you know that the change in the independent variable actually is responsible for the change in the dependent variable?