Who Does Facebook Think You Are Searching For?

Hi, my name is Keith Adams, and I worked on Facebook's typeahead. The system has evolved a bit since we launched, but I talked about first_degree.php in the tech talk we did about the typeahead back-end last year:<p><a href="https://www.facebook.com/video/video.php?v=432864835468" rel="nofollow">https://www.facebook.com/video/video.php?v=432864835468</a><p>Briefly, first_degree.php returns objects you're directly connected to in the graph, and if there's space a few machine-generated guesses at other good results. We preload these as soon as you focus the "Search" box at the top of the page, in the hopes of having some decent results to show when you start typing. The index field does, as the article inferred, represent our best guess at a ranking function on these first degree objects. The inputs to this ranking function explicitly <i>do not</i> include other users' behavior on the site. I talked a bit about our ranking function in this quora question:<p><a href="http://www.quora.com/How-does-the-new-Facebook-search-engine-know-what-Im-thinking/answer/Keith-Adams" rel="nofollow">http://www.quora.com/How-does-the-new-Facebook-search-engine...</a><p><i>Edit</i>: To clarify what a lot of people seem to be wondering, visiting someone's profile does not affect the search results of anyone but yourself.

Boy, this would be a great way to hijack Facebook accounts. Just convince a bunch of people to run your bookmarklet on their Facebook profile.

Out of my top ten, seven are women I have had a crush on at some point. Seems they are on to something...

Those who don't want to run the script can visit the facebook first_degree page[1], search for "path" in the output. Note that you need to replace your facebook id in the link which can be obtained via graph api [2].<p>[1] <a href="http://www.facebook.com/ajax/typeahead/search/first_degree.php?__a=1&#38;filter[0]=user&#38;viewer={your_facebook_id}" rel="nofollow">http://www.facebook.com/ajax/typeahead/search/first_degree.p...</a><p>[2] <a href="http://graph.facebook.com/{your_vanity_name}" rel="nofollow">http://graph.facebook.com/{your_vanity_name}</a>

Would it be possible for somebody to create a virus that would grab this file and publish it to people's profiles? I think I'd crawl into a hole and die if my ex girlfriend discovered how highly she ranked...

This is pretty funny in the ajax code:<p><pre><code> success: function(result) { alert('Please try again.'); }, error: function(data) { var text = data.responseText; // ... processes the data here... } </code></pre> Why is success error and error success?

Looked at mine. First thought: whoa, I hope no one else <i>ever sees this</i><p>Facebook you scary.

My roommate is infatuated with this girl he's known since HS. I just ran it on his laptop and she's at -68. Everybody else is above -4.<p>Can anybody beat that?

1. This is very cool 2. This is very scary. Someone hacking me then posting the top 10? Social disaster

Here's how the top 209 people in the list rank for me (the whole list was too long for me to bother cleaning up at 1:30am). 22 people had rankings of less than zero. <a href="http://i.imgur.com/WqcKF.png" rel="nofollow">http://i.imgur.com/WqcKF.png</a>

Tried browsing through the javascript to see if you're screwing with me somehow ... got too lazy 1/3 way through and decided to trust that as a member of HN community you wouldn't (probably a terrible idea). But yea, the script works ... all too well.

I might be one of the few here who has a facebook account with 0 friends and never really use it. So the results are very interesting as they contain people who I know but do not interact with. Some of them must be from profile searches I have performed but I cannot explain the others. I am inclined to believe they must be incorporating 'other users behavior on the site'.

If you have folks with non-ASCII names, here's a Python three-liner to convert the output of first_degree.php to a text file:<p><pre><code> with open("first_degree.php.txt", "w") as f: for e in json.loads(open("first_degree.php.json","rb").read().replace("for (;;);",""))["payload"]["entries"]: f.write(("%s %r\n" % (e['text'],-e['index'])).encode('utf-8'))</code></pre>

I'm curious whether these numbers factor in people who are looking for you/interacting with your profile. My list has some people I don't recognize as well people who I definitely have not clicked anything of recently, which is why it might.

I'm not a frequent Facebook user but I log in at least once a day. The first person on my list is a girl I am dating who is about a -2. I am the second person on my list also at about -2. About 30 more people have a negative number. The remaining people (about 500) are all a positive number. I don't even know who many of the people are at the bottom of my list.<p>It is interesting to note however that my brother is a frequent Facebook user and his first person on his list ranks at about a -26, and EVERY SINGLE person in his graph is assigned a negative number. Despite this, he still doesn't know who a lot of the people are on the bottom of his list.<p>Other things I noticed: - Some people that I barely even know but just became friends with are ranking highly on my list. I imagine this is because I probably viewed a bunch of their pictures after being friends, combined with the fact that I don't often view profiles of people I am friends with.<p>- Some of my more recently added friends have the same exact value.<p>I wonder how much information could be extracted about the algorithm by creating a dummy community of people and connecting them together, then recording the results. I imagine much of the algorithm could be reverse engineered by this if anybody were up to the task. I will probably work on it if nobody else does and publish my findings.<p>EDIT: Explained what I was trying to say better, fixed grammar.

I think it's a bit funny that with a score of -0.3 I am #2 on my own list (#1 being a girl who's profile I checkout a bit too often), I'm stalking myself??<p>That said, I've always thought it was strange how FB comes up with the people not only in search but also the ten friends list on the left in profiles, the chat list on the right, and 'people you may know'. I've done a few tests w/ friends regarding the topic, and pretty much what everyone here has guessed seems to be true. There's a very good chance FB factors in people who are looking for you/interacting with your profile (unreciprocated), but of course they won't admit that..<p>I don't think it's such a big deal in either case. The top Chinese Facebook-like SNS site, <a href="http://renren.com/" rel="nofollow">http://renren.com/</a>, shows everyone the most recent 9 visitors on a page, and its often used (by would-be stalkers) as a way to overtly show interest "hey, i'm checking you out" kinda deal, or for couples to let each other know they are attentive. Otherwise, its just friends keeping tabs on each other. I'll admit, at first I was weirded out by it, but now it seems almost normal.<p>I'm probably way out of the norm here, but I honestly wouldn't mind having this in FB.

That is really strange to me. Maybe I don't stalk enough or something, but often when I look up a friend (someone who is actually in my friend list and I communicate often with) it seems to be impossible for Facebook to find this guy and I have to go directly to the friendlist search to get this person's profile. Always (or so often that I don't remember the exceptions, which is in usability terms "always") when I use the normal search bar I get people I don't know, have not even indirect relations with or be in any way interested in. Sometimes the names don't even consist of the words I was putting in the search bar. That's why I really wonder why people can think of facebook's people search as something cool or "stealable".

As some have mentioned, doing a couple of tests with dummy accounts seems to indicate that a friend visiting your page can influence your first_degree.php, which would explain why there are a few people who you never stalk who happen to be on your list.

Thanks for all the comments and feedback on the bookmarklet. Glad it was entertaining. As mentioned by other commenters, the popularity of something like this does raise many interesting security issues.

Facebook rape (posting embarrassing statements when using a friend's account) is common. What happens when facebook rape becomes "post who your friend has a crush on"?

Not knowing much about facebook API, tried plugging in somebody else's profile ID instead of "Env.User". Thank God it came back with "not authorized."

The bookmarklet doesn't work if you have secure browsing (https) enabled on Facebook. As you should.

Time to run this script on my crush's profile to see if I am on her top of list or not.

is facebook censoring this? i tried to post the link to the thekeesh.com page to a friends 'wall' and everything in my comment after and including the link was elided. Or maybe facebook post entries are always that broken.

I just noticed how incredibly fast Facebook search is

Facebook excels at making sensational frontpages with pretty vanilla technology.

that's a damn bad design. I stared at my laptop for a while to a bunch of hats?

Luckily as I read this (and my significant other read it over my shoulder) all my top matches are close male friends and my brother (and her).<p>Seriously though, this is a bit on the creepy side Facebook.