he had a dream that whites and blacks will soon be one.
that is one.
that would be burlington?
in this case, the independent variable is the food given or the absence of it, since the dependent variable is the object of attention, study. as we can see in this example the other conditions in an experiment are controlled, (volunteers are presented healthy, and is everything else is assumed remains in control.. cetereis paribus).
independent variables are modified by the researchers in order to notice changes and then validate or invalidate the thesis, that is they are putting into experimental validation this variable. this is a common feature in the scientific method.