You are working for an automotive parts manufacturer, and are responsible for product testing new braking technologies. Specifically, you are tasked with testing if new tire designs or new brake pad designs will improve vehicle stopping distances (at highway speeds, in standard driving conditions). You have 200 different vehicles to test on, ranging from small compact cars to large trucks. Similarly you have a well controlled test track on which to conduct your experiments. Last minute you are called to a very important company meeting, and instructed to let your staff handle the experimental data collection. Unfortunately, though your interns are diligent and well intentioned they do not have a good understanding of experimental design, and left to their own devices will do whatever it is they find easiest to complete the objectives set before them.

Give a set of instructions for your interns to follow to conduct a thorough experiment for assessing whether new tire designs, new brake pad designs, or both improve stopping distances for various car types. Be sure to be explicit in what the interns should record, how they should conduct the experiment, and anything else you think would be important for them to consider.