How to test such a prediction? First, we have to simplify matters: obviously, the air exerts forces on objects, such as leaves and paper, which fly off the ground under the influence of wind. To test our hypothesis, we need objects that will show little effect due to wind resistance. Secondly, we need a means of measuring the time elapsed between release of the object and its arrival at the ground. This requires that we develop some method for controlling the release of the object with respect to the intervals of our timer.
Many more such decisions must be made. While these decisions seem to increase the complexity of our study, in fact their purpose is to simplify the execution of our experiments. We simplify and control the phenomenon under study to improve the reliability of our conclusions regarding our hypothesis.