Tree-Based Commenting Systems & Quickly Decaying Threads
I've been browsing Tildes a bit today and, overall, am enthusiastic about what I've seen. However, while reading a thread, a thought popped into my head that was evocative of an issues Reddit and other tree-based systems suffer from — thread freshness and activity over time both decay quickly.
While reading the thread, I thought "I would comment, but there already seem to be a lot of comments here. If I reply to a specific tree, then that limits people who might see it and respond. Even a top-level comment probably won't be likely to get much of a response."
On Reddit, this leads to repost after repost of the same content in brand new threads, as the activity level of a thread decays and the thread is lost. It looks like one way you intend to combat this is with different sorting methods (Newest, Activity) over various time periods (all time, last 3 days, etc.). Do users feel that this will be effective enough itself, or do they have other ideas to combat this issue?
The way I generally see it, linear threads often beat out tree threads when it comes to keeping threads alive without users having to read through a lot of crap to figure out what the current topic of discussion is, and where it's taking place. (Linear threading models to think of are phpBB, vBulletin, IP.Board, and their ilk. Tree threading models are sites like Reddit, Slashdot, or Shacknews. There are also hybrids, like Metafilter. Please share other examples and their pros/cons.)
In a tree system, I've often experienced the following sequence:
- Read all top-level replies
- Read most sub-level replies
- Find where in the tree the most recent discussion is occurring
- Realize it's not coherently taking place in one tree
- Decide not to reply
While in a linear threading system:
- Read past 2–3 pages of replies to get caught up
- Add a reply
Alternatively, the linear threading sequence can also be:
- Read entire thread to see how it's evolved over time
- Add a reply
An added benefit that is usually concomitant to a linear threading system is that threads are easy to "reactivate" (AKA gravedig) — simply add a new reply and the thread gets bumped up the stack for all users. This is not an exclusive benefit of a linear system. It could likely be made to work with a tree system too. The Activity sorting method may be related, though it's unclear how this functions.
Linear threads work for very focused conversations, but with this many people actively commenting the thread would become an incomprehensible mess for anyone who is late to the conversation. Unless they read every single comment, which most people don't have time for.
A partial solution to this has been implemented on most linearly-threaded systems — quoting of previous comments. It becomes clear who is replying to whom when the entire previous line of the discussion is quoted. Additionally, quotes can nest infinitely.
An unfortunate side effect is that they take up space. When you have to scroll through the same quotes several times, it can become tedious.
And some forums don't allow quoting more than the previous X posts (back when I regularly visited forums, I saw 3 and 5 as common limits). It does help reduce the amount of redundant walls of text, but is less helpful if you jump several pages forward. Plus, some replies are still really long, and you might be forced to truncate quoted posts.
I think the main problem with linear threads is that it makes it very hard to reply to one another (commenter to commenter) and follow/read these replies, for clarity, I think it's best to have at least a single depth (like YouTube comments). But personally, I actually prefer it the way Reddit/Tildes has it now (infinite depth).
This exactly. Yes, the linear threading model allows you a better chance for your comment to be seen, at least for 5 minutes until it gets buried in a popular thread, but it makes it nearly impossible to have actual extended conversations.
The linear system is primitive and does not scale well at all in high-activity posts. Threading at least allows for ongoing discussion.
I'm really not certain about this, but something I've thought about a little is that you could probably do both as alternate views of the thread. Since we already have the tree structure, you could display it as a linear thread where each comment just says which one it's in reply to (and probably allows expanding the replying-to comment to see it).
That's a very interesting idea though I wonder if it would cause confusion for those that think they're responding to the last few comments in the linear format, but in actuality are creating a new branch in the tree format.
Another idea I think would be interesting is if there was a way to respond to multiple comments in one response, to sort of bring branches back together, or to summarize what the multiple branches are saying.
Having the option of a linear structure might also foster a culture of quoting relevant parts of the the parent comment, which I see as a strong positive.
The question is how long should a thread keep going, part of the reasons that trees die is because all has been said.
I do believe there is an issue with the tree thread that you can't respond atop multiple branches. Maybe a solution to that would solve the other issues as well.
In the traditional linear model, like on vBulletin or phpBB boards, threads die organically — they fall off the first page or two of threads — until there is something new to say. The, a user posts and bumps the thread to the first page.
Maybe some way to braid the comment that's 5 deep in a thread, but interesting, back into the top level comments? Like how r/bestof finds gold like that and reposts it for all to see