how metafilter works??

March 5, 2016 1:20 PM

i want to study about metafilter. when a person ask a question similar question that in the past asked by other user will show to the active user. this work called recommendation. i want to know how metafilter recommend similar question to the active user??
posted by msmryh to MetaFilter-Related at 1:20 PM (21 comments total)

You mean the "related posts" at the bottom of the page? At a first approximation, it has to do with the associated tags and the category (for example, "home and garden") the post is in. pb may be able to talk more about it when he's in.

As with everything here, if you notice a weird match or someone seems to be trying to game the system, you can let us know and the moderators will be on it quickly.
posted by LobsterMitten (staff) at 1:25 PM on March 5, 2016 [1 favorite]

Or no, it sounds like maybe you mean the "here are some similar posts, do they answer your question?" box that is shown on the Preview page when posting a new question to AskMetafilter. I believe those work similarly to the "related posts" on the bottom of the page for AskMe questions.
posted by LobsterMitten (staff) at 1:27 PM on March 5, 2016 [1 favorite]

Sure, here's a quick summary. Ask MetaFilter questions are organized by categories that users choose and tags that users enter. We then look at how frequently tags are used and assign them a score. If a tag is used frequently it gets a lower score than one that is used infrequently. So the tag Art has a score of 1 while the tag Picasso might have score somewhere around 6.

So when someone is posting a question they include some tags. If it includes the tag Picasso we're going to score past questions that also have that tag as more related than other questions. Then we repeat for every tag included. If a past question is also in the same category, we bump the score up even more. Then we return the top-scoring previous posts.

We use this same calculation to create the Related Questions box at the bottom of Ask MetaFilter threads.
posted by pb (staff) at 4:09 PM on March 5, 2016 [34 favorites]

it's called cognition without cortex.
posted by quonsar II: smock fishpants and the temple of foon at 7:31 AM on March 6, 2016 [16 favorites]

This is a whole subfield of a subfield of computer science, called collaborative filtering. The best open-source project for implementing for smaller recommenders is mahout's non-distributed mode (taste), because when you get bigger you can have a less awful experience shipping it to mapreduce. There is also an in-memory distributed recommender in spark which I've heard is pretty alright. These are more heavy-duty systems, tho. The old penguin book (Programming Collective Intelligence) has a walkthrough on building one from scratch with Python.

Ullman, Rajaraman and Lekovec are writing a book about it which is good if you have a lot more math background.

I've heard from the Stanford Infolab kids that the best collaborative filtering out there is actually in pinterest.com, because that's basically their lifeblood.
posted by hleehowon at 7:32 AM on March 6, 2016 [6 favorites]

Well, what Metafilter actually does sounds more like content-based filtering, although it only uses the tags and not the entire post body. A collaborative filtering approach might look at which users have favorited the post, and recommend other posts that most of them also favorited.
posted by Rangi at 10:55 AM on March 6, 2016 [4 favorites]

It's called cognition without cortex.

Au contraire, mon quonsierre, there is no cognition without cortex in this regard.
posted by y2karl at 3:17 PM on March 6, 2016 [4 favorites]

quonsar II: smock fishpants and the temple of foon: "it's called cognition without cortex."

I guess it's cognition without mathowie now, amirite?
posted by double block and bleed at 3:29 AM on March 8, 2016 [1 favorite]

Maybe cognition is too strong a word for computers. It's not like they understand and judge our words and tags with minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarding us with envious eyes, and slowly and surely drawing their plans against us.
posted by double block and bleed at 3:38 AM on March 8, 2016

I guess it's cognition without mathowie, now, amirite ?

No, comment without consciousness is more the rule.
posted by y2karl at 12:19 PM on March 8, 2016

Pay no attention to the man behind the curtain!
posted by Nanukthedog at 12:22 PM on March 8, 2016

We do need a prediction algorithm around here, but for answers. So the next level down would be "here are answers to questions like yours" based on best answers and favorited answers:

Dear AskMe. Should I do this? Or not?

Here are some recommended answers!
DTMFA
Therapy
No really, cognitive behavioral therapy
Declawing is inhumane
IANAD but yes go now right away
Macbook Pro
posted by spitbull at 1:17 PM on March 8, 2016 [5 favorites]

Refurbished Thinkpad.
posted by Too-Ticky at 3:00 PM on March 8, 2016 [4 favorites]

Please hoped!
posted by klangklangston at 9:24 PM on March 8, 2016

how metafilter works?

Hi, msmryh - one way metafilter works is by lurking moar.
posted by progosk at 11:31 PM on March 8, 2016 [1 favorite]

Yeah, WCityMike, that subroutine maxes out the CPU on a refurbished Thinkpad anyway.
posted by spitbull at 10:53 AM on March 9, 2016

Folks, clearly the OP's first language isn't English, so let's cool it with the overly-nerdy ("lurk moar") or highly jargony comments. The first three comments are great examples.
posted by divabat at 12:08 AM on March 10, 2016 [5 favorites]

great examples of comments that WORK, I mean
posted by divabat at 12:08 AM on March 10, 2016

The very reason why I provided the non-jargony links to go with the words (the first of which is particularly topical for Metafilter newcomers).
posted by progosk at 10:48 AM on March 10, 2016

The very reason why I provided the non-jargony links to go with the words (the first of which is particularly topical for Metafilter newcomers).

I think this is one of those times when someone tells you you were a jerk and the appropriate response, whether you meant to be a jerk or not, is to keep your mouth shut. Because that was a jerk comment.
posted by hoyland at 4:55 AM on March 11, 2016 [1 favorite]

"I think this is one of those times when someone tells you you were a jerk and the appropriate response, whether you meant to be a jerk or not, is to keep your mouth shut. Because that was a jerk comment."

So, answering "How MetaTalk works?"
posted by klangklangston at 2:59 PM on March 11, 2016