A design of experiments was conducted to study the effect of various factors on the yield and taste of microwave popcorn.11 The factors and their settings were as follows:

Preheat involves heating water in the microwave for 1 minute prior to popcorn. Elevate means put a plate or something similar under the popcorn bag to raise the bag.
Fractional factorial design was used to obtain two responses: (a) Bullets = weight of non-pop ped pop corns, in ounces; and (b) taste (a score between 1 and 10, 10= best).