Any thread where the discussion isn't expected to splinter into subtopics, and the newest posts have more value than the 'best' post.
One example might be a non-trivial tech support problem, where forum members work together to solve an issue. As the user tries solutions and posts their progress, the initial post isn't as valuable as the latest one. Other examples would include threads with real-time reactions to events, like a sporting event or political debate, or threads that are longer-running, like telling a story that unfolds over time.
> Any thread where the discussion isn't expected to splinter into subtopics
But most longer running discussions will splinter into subtopics. If the discussion is short enough, the way it's displayed doesn't really matter either way.
> Other examples would include threads with real-time reactions to events, like a sporting event or political debate
I think the line between a mostly synchronous chat and an asynchronous discussion forum as been blurred a bit. In chat, it's a lot easier to follow a discussion as it's happening because you can read the messages as they come in and only pay attention to the ones you're interested in. But trying to read the log after the fact is a bit more time consuming because you have to search for the relevant messages amongst many.
In a threaded and asynchronous discussion, it's easier to go down a subthread to follow a particular discussion than it is to find that discussion mixed in with all the other posts.
That said, I find it interesting that email clients have moved towards displaying messages in a conversation view, yet newer chat clients like Slack are introducing threaded discussiion as a feature.
One example might be a non-trivial tech support problem, where forum members work together to solve an issue. As the user tries solutions and posts their progress, the initial post isn't as valuable as the latest one. Other examples would include threads with real-time reactions to events, like a sporting event or political debate, or threads that are longer-running, like telling a story that unfolds over time.