The Respondent-Generated Intervals protocol (RGI) has been used to have respondents recall the answer to a factual question by giving not only a point estimate but also bounds within which they feel it is almost certain that the true value of the quantity being reported upon falls. The RGI protocol is elaborated in this article with the goal of improving the accuracy of the estimators by introducing cueing mechanisms to direct confident (and thus presumably accurate) respondents to give shorter intervals and less confident (and thus presumably less accurate) respondents to give longer ones.
Chu, LiPing; Press, S. James; and Tanur, Judith M.
"Confidence Elicitation And Anchoring In The Respondent-Generated Intervals (RGI) Protocol,"
Journal of Modern Applied Statistical Methods:
2, Article 14.
Available at: http://digitalcommons.wayne.edu/jmasm/vol3/iss2/14