STORY 3 🍪 The legend of the scrumptious cookie
Recipes for chocolate and orange cookies include exactly the same ingredients up to the point where the syrup was added to the batch. However, after the cookies were baked, the chocolate cookies had an appealing round and plump appearance, while the orange cookies spread during the baking process and became thin, flat, and unappealing. A factorial experiment was devised to determine if there was a way to change the process of making the orange cookies that would reduce the spreading during baking. The factors that were chosen to be varied were A: the amount of shortening in the dough batch (80% of what the recipe called for or 100%), B: the baking temperature (below, at, or above the temperature called for by the recipe), and C: the temperature of the cookie sheet upon which the cookies were placed to be baked (hot out of the oven, or cooled to room temperature). The cookie-making process consists of the two steps: 1. mix cookie dough batch, and 2. bake cookies. Factor A is related to step 1, factors B and C to step 2. The amount of shortening was a hard-to-vary factor because each time it was changed it required making a new batch of cookie dough, while the baking temperature and tray temperature were easy to vary. Once a batch of dough was made, there was enough to make six trays of cookies, and all six combinations of baking temperature and tray temperature could be tested within each dough batch. First, plan to make four batches of cookie dough and randomly assign two batches to use 80% of the recipe recommended amount of shortening and two batches to receive the full amount of shortening recommended by the recipe. Next, bake six trays of cookies from each batch of dough and completely randomize the six combinations of bake temperature and tray temperature to the six trays of cookies within each batch.
