PG: What's your current take on reddit's comment system?

http://reddit.com/info/17844/comments/c50

by brett • 19 years ago

21 64 19 years ago

While reddit's comment system is obviously an improvement over Slashdot's, I'm increasingly convinced that the community is more important than the tool.

brett3• 19 years ago

While reddit's comment system is obviously an improvement over Slashdot's, I'm increasingly convinced that community makeup is far more important than the tool it uses.

pg3• 19 years ago

I agree, basically. Except I think customs are as important as or more important than makeup. That's why I try to discourage ad hominems.

To be fair to the reddits, it wasn't their fault that the discussion on reddit sank down toward that of digg and slashdot. They have really strong beliefs against censorship. They were never going to jump into a discussion and tell people to stop being jerks. But empirically it looks as if you may have to.

The optimistic way of phrasing this is: if you have good customs and existing users enforce them, you can probably survive the influx of 14 year olds when it comes.

brlewis• 19 years ago

Did anyone point out to the reddits that telling someone to stop being a jerk is not censorship?

brett3• 19 years ago

That really interesting; your emphasis on community custom is not something I'd really thought about. You could even go so far as to classify reddit's innovations as an attempt to programatically encourage or enforce such customs. I wonder if you could take it further programatically. Off the top of my head you could go the email route and switch to a three button system for comments: "up", "down", and "troll". I'm guessing you can tell where I'm going from there: A Plan For Trolls?.

byrneseyeview3• 19 years ago

"They were never going to jump into a discussion and tell people to stop being jerks."

Really? Isn't that more or less what they did with Pica when they requested that he stop using certain epithets?

bes• 19 years ago

Lowtax (he runs somethingawful.com) gave a talk about web communities at UIUC a few years ago and he basically said without good moderation large sites will just degenerate into crap. The talk(http://www.acm.uiuc.edu/conference/2005/video/UIUC-ACM-RP05-...) takes 15 minutes or so to get into anything serious, but I think there are some good lessons in there.

brett3• 19 years ago

Incidentally I came across this while trying to find information about how reddit stores threaded comments. I've read they use postgres and while I've also read about many workable techniques to force hierarchical (and frequently reordered) comments into a relational db these solutions all sort of make me cringe. I'd welcome anyone's ideas here as well.

aston2• 19 years ago

I did a quick and dirty forum a couple years back that now serves up hundreds of new threads a day (having tens, sometimes hundreds of messages each).

My solution was to store a comment thread in display order in the database with hinting as to how deep in the heirarchy the comment is. Optimizes for output, although with some cost every time something gets posted. Luckily, for most forums, views outnumber posts by hundreds of times.

The one issue that system has is that if you're doing a lot of reordering, let's say from quality scores. In that case you'll basically have to remake the thread after every post and after vote that makes a difference. Not recommended...

twism3• 19 years ago

i am in the process of making a news.yc clone... threaded comments are not as easy as it looks on news.yc.

[edit] especially when the comments get reordered on votes.

aston2• 19 years ago

If you're trying to mimic this forum with a database solution, it's going to be a pain. PG's keeping this stuff in memory, almost certainly as the tree that it is.

edit on the edit: scratch that.

euccastro2• 19 years ago

What's hard about threaded comments, exactly?

nostrademons7• 19 years ago

The approach I took on Diffle (http://www.diffle.com/ - unfortunately it hasn't been exercised as we haven't really got traction yet) was to store the comment ID as a varbinary(255). A child comment takes the ID of the parent and then appends a 2-byte sequential number. So, the first comment is 0x0001, the second is 0x0002, a reply to the second is 0x00020001, a second reply is 0x00020002, the third is 0x0003, a reply to the third is 0x00030001, etc. To find the children of a comment, you look for all comments where the parent's ID is a prefix. MySQL can use leftmost-prefixes as indexes, so this computes very quickly. Also, with the standard varbinary collating order, 0x01 sorts before 0x0101, 0x0102, 0x02, etc, so all I have to do is order by the ID and everything will come out in proper threaded order. And nesting depth is calculated easily by len(id) / 2.

Reordering can be done just by looking at all records whose IDs contain the parent as a prefix and have a length 2 greater than the parent, and then renumbering them. This should be computationally feasible in most cases.

This does limit users to 65,536 replies to a single comment, and a maximum comment nesting depth of 127. Based on my experience with some very active LiveJournal threads, I considered these to be acceptable limitations (LJ limits comments to 5000/post anyway). A nesting depth of 127 would be nearly 2400 pixels over, so it's not like it'd all fit on one screen anyway.

vlad2• 19 years ago

Why not just store the parentid (can be another comment or the news topic), username (instead of userid so you don't have to access the users table), and votecount for each comment?

Also, each comment should have a newsid field that points to the original newstopic. The left-most posts would have the parentid and newsid that were the same (or parentid can be zero, depending on how you do it). But any replies would have the parentid to the parent comment, but the newsid would still point to the newstopic. Then you just run an SQL query to find all comments with the newsid for that newstopic. You won't have to join any tables. After that, with everything in memory, you can just sort the way it has to be. Finally, you can cache the page in memory or a file in case the page doesn't change for the next set of visitors.

transburgh2• 19 years ago

The one issue I have with the comments are they are not in chronological order and reorganize as new posts are added. It is annoying to figure which messages you have already read and which you have not since they are all mixed together. A simply chronological thread would be nice.

bls• 19 years ago

On the right hand side of the screen, you can sort the comments chronologically.

transburgh2• 19 years ago

Thank you. Never saw that before. That should be incorporated on YC News.

Alex39172• 19 years ago

On the topic of community makeup, here are some interesting findings that come from Yahoo's social scientists (using Yahoo lists as the dataset):

1) Small groups have higher numbers of core users

2) Private and semi-public groups have higher numbers of core users than public groups

3) People in private groups remain in the core for longer

4) A user who is in the core of one group is more likely to become a member of the core when joining another group

5) New members who eventually become part of the core are more likely to receive messages from other users who have been long-time core users

6) New members who eventually become light users are more likely to receive messages from other light users, if they receive replies at all.

This suggests some strategies for building a strong group of core users to transmit social norms. For example, having an idea of who the core users are in other similar communities and making a special effort to reach out to them if they visit your site.

Unhappily I lost the original paper and all I have are my notes, so I don't know exactly how they defined the core users offhand.

Jd14• 19 years ago

Alex, this is very interesting. Do you think there might be a way to get one's hands on the original? If there is a person/persons at Yahoo to contact I would do it, as this is something I have thought about quite a bit and would love to see more about the definitions of core, light, new, long-time, large and small.

You can email me if you like.

Alex39172• 19 years ago

So I heard this talk at the Cornell Microsoft International Symposium on Self-Organizing Online Communities. The presentation was called "Implications for Future Research; Theory and Methods in Large Scale Analysis of Online Communities." And the three Yahoo presenters were Ravi Kumar, Andrew Tomkins, and Cameron Marlow. Not sure which one those three specifically, but I'm sure you could ask any of them.

I've developed this hobby of sneaking into academic conferences. It works best if when everyone else is wearing a suit and tie, you show up in shorts and a t-shirt. That way everyone just assumes that you're friends with one of the speakers, or else that you're Sergei Brin. :-)

whacked_new5• 19 years ago

I suspect these findings will apply to a certain type of "community." It does not, for example, apply easily to the wikipedia community.

What would be equally interesting as these findings, are the premises. What service, what content, what medium, what purpose, and extremely importantly, how presented.

naivehs• 19 years ago

I would like if there is a function to hide and expand the comments. For example one click on a comment will hide itself and all its sub-comments. It is a good way to organize the discussions, and I always believe a website is at its best when scrolling is minimized.

acgourley2• 19 years ago

I have the same problem with reddit and digg: I like to read exceptionally downmodded comments. When comments get modded down so much that they are not displayed, and also they generate a lot of responses, it's the kind of thing I can help but look at. Like a train wreck I suppose.

It actually sucks me into the troll MORE when they get such special highlighting. I should say I do like how top level troll posts get put at the bottom for reddit.

deramisan• 19 years ago

It bugs me that downmodded comments trash karma - political disagreements often get downmodded not because they aren't valid, but because someone disagrees fundamentally. That doesn't seem right.

icky• 19 years ago

Reddit comments DO NOT AFFECT KARMA.

Only submitted articles do.

I have no idea how you got any different idea into your head, but it was not through observation of reality.

mlgoss• 19 years ago

You can set the threshold or turn off the hiding of downmodded comments on reddit.

acgourley2• 19 years ago

If anyone is interested in a blog post about the problems with comment and forum systems in general, here is something I wrote on the subject: http://www.digitalkarate.net/?p=20

dantheman• 19 years ago

I'd like to see 2 modderation options.

1. The standeard up/down arrow -- does this contribute to the debate, is it a troll etc. 2. The agree/disagree poll. This could be a thumbs up/thumbs down.

PG: What's your current take on reddit's comment system?

Related Stories