The bogus pipeline is a fake polygraph used to get participants to truthfully respond to emotional/affective questions in a survey.
It is a technique used by social psychologists to reduce false answers when attempting to collect self-report data.
[1] The bogus pipeline was first used in the spring of 1971 by psychology professor Harold Sigall at the University of Rochester.
In this technique, the person whose attitude or emotion is being measured is told that they are being monitored by a machine or a polygraph (lie detector), resulting in more truthful answers.
However, participants end up telling their true feelings and attitudes because they believe they are being monitored and that the real answers will surface regardless of their response.