DialogMapping, also called ArgumentMapping or DiscussionMapping, is a technique for using graphics to display the structure of reasoning and argumentation. It is used for CriticalThinking and for solving WickedProblems. DialogMapping is often used by trained facilitators or technographers. DialogMapping is somewhat related to MindMapping or ConceptMapping.
The IssueBasedInformationSystem (IBIS, pronounced eye-bis) is a method developed in the early 1970's for DialogMapping, and an online tutorial is available. There's an work-in-progress formalization of the IBIS terms for use in XML/XTM/RDF applications at http://purl.org/ibis.
The data model for DialogMappingExtension would be a single "dialog relation" (idea, question, or pro or con argument) relating an entire entry to another (possibly using a ThreadingExtension) or a collection of relations with finer-grained links.