Researchers often use mock-ups of the final creative with varying degrees of finished artwork. Some mock-ups are only intended to be seen by the advertising agency and client during the advertising concept development stage. However, mock-ups are useful for gauging audience response to the proposed advertising copy. Mock-ups can be used in face-to-face interviews, small focus groups or theatre tests. A sample of respondents is invited to look at the mock-ups and subsequently asked a series of questions designed to capture advertising effects that are of interest for the given campaign.