Marketing Research firms often have exclusive rights to doing interviews in shopping malls they have contracts with. They also often maintain facilities within the mall. Such firms might set up an artificial store within the mall to test advertising or sales promotion associated with such a store. Discuss the type of experiment being conducted if the marketing research firm offers an incentive to persons in the mall, such as those participating in mall intercept interviews, who would be observed as they interact with the promotional materials in artificial store.