A researcher wants to see if an aspirin advertisement increases sales if it uses a doctor spokesperson instead of a kindergarten teacher spokesperson. Sales of the aspirin brand are measured prior to the implementation of the advertisements. For one month, the advertisement with the kindergarten teacher spokesperson is shown on television, and sales are measured. For the next month, the same type of advertisement is run but the spokesperson is identified as a doctor. Sales are measured again.
Independent Variable:
Dependent Variable:
