In a scientific experiment, what is the control variable for?

Question

Please help, i don't really get what it's for! Thanx in advance

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Answer 1

The control is for two things.

One, it will confirm that the experiment works as it should (e.g. in a bacterial experiment, a control can confirm sterility of the growth media).

Also, a control will give you the "zero response" if you use it for a calibration, in which case it is also known as a blank.

Answer 2

There are 3 variables which can be identified:

-manipulated variable: factors which are changed during experiment

-responding variable: factors that change according to changes in manipulated variable

-fixed variable: factors which does not change at all during experiment

In a scientific investigation, one variable is manipulated to study its relationship with a responding variable.

Answer 3

the control is used so that you have something to compare the results of your experiment to.  The control is unchanged throughout the experiment.

Answer 4

control variables establish baselines. There are expected statistical results from the status quo & they should be accounted for prior to altering the test poulation.