Methods and systems provide for establishment of online dialogs between a person and a user of an online community where those people are not necessarily familiar with each others areas of expertise or interests. The methods and systems can categorize a dialog topic received from the person, and determine, from categorization of users, a selection of users of a system to receive the dialog topic. That selection can be further narrowed according to user availability and/or ranking determinations, as well as an initial subject matter test posed to the selection of users. Judging the acceptability of the users' responses can help determine subject matter expertise in an area relevant to the proposed topic.