A food scientist wishes to study the effect of the type of pan and amount of sodium bicarbonate used in preparing peanut brittle on the flavor of peanut brittle. In an experiment, peanut brittle is baked in two types of pans (aluminium, non-stick stainless steel) using 2 or 4 grams of sodium bicarbonate in the recipe. Four batches of peanut brittle are prepared at each combination of pan type and the amount of sodium bi-carbonate. A panel of 4 tasters scores the brittle on the intensity of peanut, sweet and buttery flavors.
(a) How many different treatments are there in all? How many batches of peanut brittle are going to be baked in all? Show the calculation you make.
(b) Explain why it is a bad idea to bake all four batches for one treatment first, then bake all four batches for the second treatment and so on.
(c) Explain why it is a bad idea to have each taster score all four batches from one treatment.
(d) Construct a design that blocks on tasters, and also randomizes both in the baking and the tasting stage. You do not have to do the randomization, but clearly explain how the experiment will be conducted.