6.1 The perfect cup. One method for brewing coffee is the pour over. Ground coffee is placed in a filter-lined dripper (a metal or ceramic basket with holes in the bottom that fits over a carafe). Hot water is poured over the coffee and allowed to drip into the carafe. A coffee shop carries three brands of dripper, each brand differing in shape and the placement of holes through which the coffee drips. Some experts believe that moistening the filter with hot water before filling with grounds affects flavor, so the coffee shop plans the following experiment. For each brand of dripper, coffee is to be brewed both with the filter moistened and with the filter dry. A trained barista will brew two cups of coffee for each of the six combinations of dripper and wet/dry filter. A panel of trained tasters scores each cup for flavor on a scale of 1 to 10, with higher scores indicating better flavor.

What are the explanatory variables and the response variables for this experiment? Make a diagram like Figure 6.1 to describe the treatments. How many treatments are there? How many cups of coffee will be brewed?