Organizing the scope of weathering test methods into logical order helps the engineer visualize tools available for weathering tests. One order organizes exposures showing those with slowest rate of degradation on one extreme through the exposures showing the fastest rates of degradation on the opposite extreme. An example of this order may place the end use environment of an automobile in rural Michigan towards one end, at latitude exposures in Florida and Arizona farther along, sun tracking and EMMAqua exposures farther still, up to harsh artificial laboratory methods such as high irradiance xenon or metal halide exposures towards the other end. Organizing exposures in this manner points out a primary consideration for the engineer; a trade off exists between acceleration (speed of obtaining testing results) and confidence (types and rates of degradation are what is actually observed in the end use environment).