APA Dictionary of Psychology

fake apparatus used in attitude research to ascertain attitudes toward controversial or sensitive issues, about which participants would otherwise be tempted to answer dishonestly. The apparatus is attached to the participant, who is then informed, incorrectly, that it can detect whether the attitude they report is a true one. In one study, it was found that use of the bogus pipeline resulted in a greater likelihood of admitting cocaine abuse, excessive drinking, and oral sex.