Does the color of a food or beverage affect the way people perceive its taste? In this activity you will conduct an experiment to investigate this question and analyze the resulting data using a chi-square test. You will need to recruit at least 30 subjects for this experiment, so it is advisable to work in a large group (perhaps even the entire class) to complete this activity. Subjects for the experiment will be assigned at random to one of two groups. Each subject will be asked to taste a sample of gelatin (e.g., Jell-O) and rate the taste as not very good, acceptable, or very good. Subjects assigned to the first group will be asked to taste and rate a cube of lemon-flavored gelatin. Subjects in the second group will be asked to taste and rate a cube of lemon flavored gelatin that has been colored an unappealing color by adding food coloring to the gelatin mix before the gelatin sets.

You may choose to use something other than gelatin, such as lemonade. Any food or beverage whose color can be altered using food coloring can be used. You can experiment with the food colors to obtain a color that you think is particularly unappealing!

1. As a class, develop a plan for collecting the data. How will subjects be recruited? How will they be assigned to one of the two treatment groups (unaltered color, altered color)? What extraneous variables will be directly controlled, and how will you control them?

2. After the class is satisfied with the data collection plan, assign members of the class to prepare the gelatin to be used in the experiment.

3. Carry out the experiment, and summarize the resulting data in a two-way table like the one shown:

4. The two-way table summarizes data from two independent samples (as long as subjects were assigned at random to the two treatments, the samples are independent). Carry out an appropriate test to determine whether the proportion for each of the three taste rating categories is the same when the color is altered as for when the color is not altered.

Transcribed Image Text:

Treatment Unaltered Color Altered Color Not Very Good Taste Rating Acceptable Very Good