A colleague has approached you for help with an experiment she is conducting. The experiment consists of asking a sample of consumers to taste five different recipes for meat loaf. When a consumer tastes a sample, he or she will give scores to several characteristics and these scores will be combined into a single overall score. Hence, there will be one value for each recipe for a consumer. The literature indicates that in this kind of study some consumers tend to give low scores to all samples; others tend to give high scores to all samples.
a. There are two possible experimental designs. Design A would use a random sample of 100 consumers. From this group, 20 would be randomly assigned to each of the five recipes, so that each consumer tastes only one recipe. Design B would use a random sample of 100 consumers, with each consumer tasting all five recipes, the recipes being presented in a random order for each consumer. Which design would you recommend? Justify your answer.
b. When asked how the experiment is going, the researcher replies that one recipe smelled so bad that she eliminated it from the analysis. Is this a problem for the analysis if design Bwas used? Why or why not? Is it a problem if designAwas used? Why or why not?