A discussion that open question a series of questions about a topic(see Kaner 2007<ref>[http://knowledgecenter.completionbydesign.org/sites/default/files/198 Kaner 2007.pdf Kaner, S., Lind, L., Toldi, C., Fisk, S., & Berger, D. (2007). Facilitator’s Guide to Participatory Decision-Making (2nd ed., p. 363). San Francisco: John Wiley & Sons, Inc.]</ref>)