A technique that involves polling a group on their views on a particular issue, informing them somewhat on that issue and then polling them again.
(Pal 2006, 274)
A technique that usually involves between 250 and 600 people who form a representative sample of the community and who are first polled on their views on an issue, informed in some depth on that issue, and then polled again.
Pal. Leslie. 2006. Beyond Policy Analysis: Public Issue Management in Turbulent Times, 3rd ed. Toronto: Nelson Education.