For running the experiment, you just need to know how to set them up properly. First, you often need a control. This particular experiment pretty much doesn't have one, other than shadows being enabled. This is the basis from which the experiment is carried out from. Then comes setting up the variations. What you need is to first establish where on the screen the shadow disappears. With this now in mind, try merely panning the camera around and take notes of the behavior. Explore all possible angles with the shadow in view. Quite often, there's a pattern involved which is why taking notes is important. With all the angles tested, try changing the distance from something like 256 quants away to 512 quants away or 128 and repeat taking notes as usual. Third, try changing the viewing angle. That is, instead of the camera being south of the object, move it so that the camera is to the northeast of it or something and try it there. Finally, try different-shaped models and see what happens. Compare all your notes and look for any particular patterns. Heh, try changing the field of view once and see what happens.

Edit: This is how I carry out my experiments and give the details. Sometimes when numerical values are used, charts and graphs come in handy (as with my performance graph of which uses a logarithmic scale). It's actually fairly close to the scientific method.