A new soya milk product is being marketed to lactose-intolerant customers. The company wants to test the attitudes toward soya milk as a substitute. Two random samples of 100 lactoseintolerant individuals are selected. One group is given samples of the new product to taste. Both groups are then measured in terms of their attitudes toward soya milk.

a. Identify the dependent and independent variables in this experiment.

b. What type of design was used?

c. What are the potential threats to internal and external validity in this experiment?