Two study designs are described here. Which statement is a correct interpretation of the designs?
Design A: A supermarket wants to explore the interest of its shoppers in the weekly store ad. So, as shoppers enter the supermarket, store employees keep track of the number of shoppers who pick up a copy of the ad that is provided on a rack inside the entrance.
Design B: A hotel wants to explore the interest its guests have in dining at its restaurant. So, as guests check in, the management provides half of its guests with a $20-off coupon that can be redeemed in the restaurant at any time during their stay. The management records what percentage of the people who received coupons actually dine in the restaurant.
Design A is an observational study because store employees will just note what naturally occurred; Design B is not an observational study because coupons could influence guests.
Design A is NOT an observational study because store employees did not make the ads available to all of its shoppers; Design B is an observational study because hotel management will just note what naturally occurred.
Design A is an observational study because store employees tried to influence the shoppers to take an ad by handing them to them as they entered the supermarket; Design B is the observational study because hotel management will just note what naturally occurred.
Both Designs A and B are observational studies because store employees will just note what naturally occurred, and the hotel management did not try to influence any of its guests to visit the restaurant.