(aka message board or forum) an electronic bulletin board on which messages are posted over a period of time. In a threaded discussion an initial post is made in the form of a question or statement. Further postings are comprised of responses to the initial post or to other postings in the discussion. The thread in a threaded discussion refers to the initial post plus all of the postings made to it.
The communications between learners and instructors in leader-led courses are via a delayed (asynchronous means, normally a threaded discussion). These discussions are know by a variety of names including forums, listservs, mailing lists, computer mediated communication.
(n.) A threaded discussion is an online dialog or conversation that takes the form of a series of linked messages. The series is created over time as users read and reply to existing messages. Typically, messages in a given thread share a common subject line and are linked to each other in the order of their creation. Threaded discussion is particularly useful in online venues where multiple discussions unfold at the same time. Without threaded discussion, the reader would confront a chaotic, unsorted list of messages on many different topics. By hyperlinking messages that share a common subject line, threaded discussion makes it easy for the reader to focus on one conversation and avoid the distractions of unrelated postings.