The two main discussion board formats popular on the internet are "Threaded" and "Flat" formats. Frequently, the choice of whether to use a threaded or flat format comes down to personal preference or availability (and sometimes ease of installation!). The threaded format, however, offers some distinct advantages over the flat format that can make a significant difference in both community participation and ease of use.

The threaded format displays posts in a logical, conversational order similar to an outline. A response is posted underneath the message to which it is responding. Each response is displayed this way, so it makes the flow of the discussion very clear, since you can easily see who is responding to whom. For example:

• Does anyone know the actor's name who plays Indiana Jones? [NT] - Teresa
• Yep! Harrison Ford! [NT] - Chelsea
• Harrison Ford, unless you're asking about the Young Indiana Jones series. [NT] - James
• Thanks! I did mean the movie! [NT] - Teresa

In the example, it's very easy to see that James and Chelsea both were replying to Teresa's question, and that Teresa was thanking James for his answer.

The flat format displays messages in a strictly chronological order, so that someone joining the conversation late will always have his message appear at the end of the discussion thread, even if he is replying to one of the first responses in the thread. This makes the conversation more difficult to follow, since you have to read (and remember) every post from the beginning of the thread, along with who posted it, to make sense of the discussion. The sense of "context" can get lost quite easily, especially since it is not immediately obvious who is responding to whom. In the threaded format, fast-paced messageboards are very easy to follow because the reader can easily see new posts as they appear and can tell how each response fits in the overall conversation.

Another benefit of the threaded format is that, for short messages, the entire message can be shown in the subject line, as in the example above. This means that conversations are not only easier to follow, but the forum host saves on bandwidth since every message does not have to be opened to follow the conversation. With flat messageboards, all the messages on a page must be opened and displayed to read any given one.