When companies conduct AB tests, do the people whose behavior is being studied typically know about the test? Yes, because by instructing users that the AB test is being conducted, the users will have a heightened awareness of the features being analyzed by the test. Companies do indicate this information in the fine print of e-mails and websites, but since such details are usually ignored by users, most are unaware. No -- users are not typically notified of AB tests. Yes -- according to U.S. law, marketers must adhere to ethical compliance rules that mandate AB test disclosure to product users