trustmetrics: TrustFlow FAQ

Paul Crowley (

ciphergoth) wrote in

trustmetrics,
@ 2003-08-15 11:26:00

TrustFlow FAQ

Updated 2006-04-10: this is about the old version of TrustFlow, which is no longer in operation. See the FAQ for the new version.

Frequently asked questions about TrustFlow for LiveJournal. Please note that I will be very rude to anyone who asks a question answered here so please read carefully before posting.

It doesn't work for me !

It doesn't work for me - it keeps saying it's overloaded: That's because it's overloaded. I'm sorry, there's nothing I can do about it - you'll just have to keep trying.
But it works consistently for my friend!: That's because once it's worked out the list for your friend, it keeps the results for several hours so it doesn't have to re-do the calculation.
It says I have no friends listed, but I have very many!: If you have enough friends listed, LiveJournal doesn't put them on your friends page directly. If that happens, my script won't pick them up - it'll treat it as though you have no friends. I don't plan to fix this (a) because it's work, and (b) because such people will load the computer too much. Sorry.
I get an error!: Please read the error carefully before telling me about it. If the error is "it's overloaded", see above. Otherwise, please quote the error exactly - otherwise how can I do anything about it?

What is it, anyway?

What do the results mean?: TrustFlow is making a guess at who is "near" your friends list; who might be on it, but isn't. It does this by looking at your friends list, and the friends list of your friends, and so on.
Is this based on who reads my journal, or interests, or what?: No. TrustFlow looks only at who is on whose friends list to make the determination; no other information is taken into account. In particular, it doesn't know anything about whose journals you are actually reading, or who is reading your journal, except what friends lists tell you.
Are the people listed in any order?: Yes; the first person listed is "closest".
How exactly does it determine who to list?: A description of the algorithm appeared earlier in this journal.
It doesn't work at all - it lists my worst enemy first!: That means it's working. That person is someone quite close to your circle of friends, who you would list except that you've deliberately decided not to. It can't tell that you don't like them; all it can tell is that they are close enough to your circle of friends that you would list them if you didn't feel that way.
It's almost a copy of the friends list of one of my friends!: Does that person have relatively few friends listed? They get extra influence on who it lists as a result.

Use the source, Luke!

Is source code available?: Source code is linked from here.
Can I make a mirror?: Please do, and please publicise it here - thanks! Note that you'll need a Unix system, and you'll need to be something of a Perl hacker to make it go. Also you may get more hits than you expect. However, I'll be glad to help you set it up.
You could improve the algorithm if you...: Feel free to pick up the code and play with it. For me LJ is only an example dataset, so I'm not interested in LJ-specific tweaks. I also want to be able to prove good things about it, like attack resistance, so any changes have to be meet that criterion. Finally the algorithm is conceptually very simple, and I'm keen to keep it that way.

Irritations and niggles

It lists deleted journals and communities without marking them as such: You're right, and this should be fixed. However I shan't make time to fix it now. If you want to fix it, let me know, and I'll discuss what a clean fix might look like. It's not too hard but there are issues.
I changed my friends list but it hasn't taken the change into account: It can take up to 30 hours to take these changes into account. Sorry!
Can you make it work for DeadJournal/uJournal/etc?: I'm having enough trouble supporting LJ users. However, it would be pretty easy for someone to make a mirror that worked on DJ or whatever.</strong>

Please feel free to post any questions not already answered here - thanks!

(Post a new comment)

	fool_in_spirit 2003-08-15 03:40 am UTC (link)
	Another reason why it might work for some people more than for others might be because of the time zone difference. I live in Europe. When I try it the morning America has still not woken up and the probability to have it working are higher than if I try on the later afternoon, when most there are more people from the states connected. Pietro (Reply to this)

	ooner 2003-08-16 01:50 am UTC (link)
	I'm not sure it's working as it should... example: on my list is vamperotica who I share exactly one friend with. not on my list is disphora who I share 4 friends and a community with. How does that happen? I just added dia, so if you look into it she might not show for that reason. (Reply to this)(Thread)

	ciphergoth 2003-08-16 02:24 am UTC (link)
	How many friends you have in common with someone does not influence their placement on the list at all. It only reads in someone's friends list after they've been put on the list. (Reply to this)(Parent)(Thread)

	ooner 2003-08-16 02:44 am UTC (link)
	Aha, ok thanks =) (Reply to this)(Parent)

	maliceshaw 2003-09-01 07:55 am UTC (link)
	Just.. added.. Dia? (Reply to this)(Parent)

	nnancy1964 2003-08-16 06:34 am UTC (link)
	Is this only for paid accounts? I've tried a couple of times and have gotten an error page... (Reply to this)(Thread)

	ciphergoth 2003-08-16 07:25 am UTC (link)
	How am I supposed to help you if you don't tell me what the error is? Did you try reading it, or this FAQ, before posting here? (Reply to this)(Parent)(Thread)

nnancy1964
2003-08-16 08:07 am UTC (link)

My apologies for being an idiot. And yes, I read both.

When I try to enter my username from a friend's page, it says:
Not Found
The requested URL was not found on this server.
You may be receiving this error as a result from maintenance or other site problems; please refer to http://status.livejournal.org to keep updated on the status of the site.

I have gotten this error on occasion for other links, including not being a paying LJ user; I also wonder if it's a site problem since I can get to the FAQ without problems.

Holding my tongue on the rest of it.

(Reply to this)(Parent)(Thread)

	ciphergoth 2003-08-16 08:11 am UTC (link)
	Now I know what the error is, I can help - hurrah! Your friend has entered the URL wrong: they've probably left out the "http://" at the beginning. As a result, your browser hasn't even tried to connect to my site; instead it's looked for a page somewhere in LiveJournal. The correct URL is at the top of this page. (Reply to this)(Parent)(Thread)

	nnancy1964 2003-08-16 08:14 am UTC (link)
	ok, last apology... I didn't see the part that asked to quote the error exactly... I work overnights and am a bit bleary eyed... hope this lowers your blood pressure. (Reply to this)(Parent)(Thread)

	ciphergoth 2003-08-16 08:15 am UTC (link)
	I only added that after you posted your message; I had thought it was common sense. It's a bit of a mystery to techie people how non-techie people expect us to be able to fix problems when all the info we have is "I got an error"... (Reply to this)(Parent)(Thread)

lovewithnoface
2003-08-28 03:20 pm UTC (link)

In agreement. Lj support gets all sorts of requests that sound somewhat like this:

"omg your faq is just not working and i totally need help...cuz like my friends list is like, just not there...plz help...thx!!!!!"

I'd put the important stuff at the top in enormous letters emphasizing the need to read what you have written...its shocking how dense people can be, but big letters seem to work really well, pulling peoples eyes in like a magnet. now whether or not they'll comprehend is anyone's guess

(Reply to this)(Parent)

	touchyou 2003-08-16 10:21 pm UTC (link)
	Great job, bud. (Reply to this)

(Reply from suspended user)

	marypcb 2003-08-18 05:38 am UTC (link)
	when it says 'please wait a minute' I read it as an indeterminate 'don't hit Refresh right this second'; perhaps if you rephrase it as 'please wait at least 60 seconds' it would reduce the load from impatient clickers like moi! (Reply to this)

guyminuslife
2003-08-18 09:53 am UTC (link)

Something I noticed was that the closest 50 non-friends for my journal are ranked by your TrustFlow in almost-alphabetical order, meaning that a group of names (like 1-3 or 6-16) shows up in alphabetical order, and when the next group (i.e. 4-5 or 17-18) comes up, the alphabetical order starts over again at the beginning. So my groups are 1-3, 4-5, 6-16, 17-18, 19-22, 23, 24-29, 30-34, 35-38, 39, 40-42, 43, 44-50.

What I'm wondering is whether I'm reading too much into this or if this is an effect of the system that your algorithm uses--going through Friends lists in alphabetical order (the way in which they are listed) to add water to each of these people's buckets. At first glance, it's pretty obvious that in general, people earlier in the alphabet would get their buckets filled up quicker because it becomes their turn earlier, but whether or not this is what actually happens is beyond my grasp of this algorithm. So I guess my first question would be whether or not this is all in my head and I should stop now before I embarass myself.

My second question is that if my suspicion is correct and the only reason

beautiful_ruin is ranked ten places higher than

whitetrashbunny is because of the alphabetical order of their names, wouldn't it be more useful to group people together based on their degree of closeness? For example:

Current listing method: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20...

New method:
1st degree (x[1] iter): 1, 2, 3
2nd degree (x[2] iter): 4, 5
3rd degree (x[1] iter): 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
4th degree (x[1] iter): 17, 18
5th degree (x[1] iter): 19, 20.... and so on.

Even if this is just a fluke of my friends list, I'd be interested in seeing how many iterations it takes to get someone's bucket full.

(Reply to this)(Thread)

ciphergoth
2003-08-18 11:57 am UTC (link)

You have figured out my dirty secret. Yes, it does use alphabetical order. I had hoped it wouldn't cause visible distortions, but clearly it is causing them.

The correct solution is to switch to using the "continuous" version of the algorithm, which doesn't take the people on the list in any order. However, this involves solving linear equations, and I don't know how best to do it.

(Reply to this)(Parent)

ciphergoth
2003-08-20 04:54 am UTC (link)

I've implemented the continuous version. I'm not ready to put it online just now, but you can be the first to know the results it gives you!

Your results as they are currently calculated:

1:beastmaster666, 2: ms_salty, 3: aries325, 4: lj_maintenance, 5: smartviews, 6: blondeangelxnf, 7: crzycat03, 8: letmeramble, 9: stargazer03, 10: littlemandan, 11: psychofaerie, 12: scubasteeve, 13: undercoverme, 14: hephaestos, 15: darkagie, 16: geenahsaigon, 17: poetic_insanity, 18: takeallofme, 19: asparagusp, 20: jadevanity, 21: kcerda, 22: negentropy, 23: angerbunny, 24: loshi, 25: serraphina, 26: anthropologist, 27: egyptology, 28: persephonesmuse, 29: erries, 30: poetjen, 31: puppet_zilla, 32: angelis85, 33: darksilence85, 34: shadowfireraven, 35: thepinkhotel, 36: knowhere_man, 37: bishounenkami, 38: bloodsong, 39: drego, 40: courtney42, 41: atti_br, 42: crazyminded, 43: doggettreyes, 44: finbardivine, 45: hurtmyfeelings, 46: krazybonefreak, 47: mescalina, 48: noth_in_silence, 49: wanderlonely, 50: andrewjthomas

Your results as the continuous version has it:

beastmaster666, ms_salty, aries325, lj_maintenance, smartviews, blondeangelxnf, crzycat03, letmeramble, stargazer03, littlemandan, psychofaerie, scubasteeve, undercoverme, hephaestos, darkagie, geenahsaigon, poetic_insanity, takeallofme, asparagusp, jadevanity, kcerda, negentropy, angerbunny, loshi, serraphina, anthropologist, egyptology, persephonesmuse, erries, poetjen, puppet_zilla, angelis85, darksilence85, shadowfireraven, thepinkhotel, knowhere_man, drego, bishounenkami, bloodsong, courtney42, atti_br, crazyminded, doggettreyes, finbardivine, hurtmyfeelings, krazybonefreak, mescalina, noth_in_silence, wanderlonely, andrewjthomas

Check carefully - the only difference is that drego is moved up two points.

So it looks like the alphabetical thing wasn't such a problem after all. However there are many other advantages of the continuous version - for one thing it's much faster....

(Reply to this)(Parent)

Odd results.

figg
2003-08-21 02:26 pm UTC (link)

QUite a hight majority of my friends have

mistersleepless on their friends list. He has two on his.

So now, when I run trust flow, those two friends are the closest. This makes sense. Except, that technically ishikara is a lot more of my friends lists, and the two friends are only there by mistersleep's account.

So, is this a good thing or a bad thing?

Will try and be more coherent on this later,.

(Reply to this)

	heartxstitches 2003-08-21 07:56 pm UTC (link)
	Okay soo. Whats the point of this? (Reply to this)(Thread)

	threepwood 2003-08-22 08:29 am UTC (link)
	To have fun? :p Do you need an intricate description of everything before you do it? (Reply to this)(Parent)(Thread)

	heartxstitches 2003-08-24 12:29 pm UTC (link)
	perhaps. (Reply to this)(Parent)

	armitige3 2003-08-22 11:37 am UTC (link)
	Great program. :) My only suggestion would be to add auto-refreshing support to the page, set to auto-refresh in 60 seconds. Otherwise, it's pretty slick. (Reply to this)

	translucent 2003-08-22 06:44 pm UTC (link)
	I've just noticed a couple of support requests from people thinking it's a list of people not on your friends list who read your journal, as though it's a kind of tracker. People read less than you think. State, in big letters? (Reply to this)

	(Anonymous) 2003-08-23 11:46 am UTC (link)
	"Got no results. Perhaps it is not an existing LJ username, or perhaps it's a community or someone who has defined no friends? Sorry!" i do have an lj name,it's not a community,and i have defined friends. ^does that just mean that noone else reads it? (Reply to this)

	mija_aloevera 2003-08-23 08:07 pm UTC (link)
	This is cool...thanks (Reply to this)

	strawberrzlove 2003-08-24 10:26 am UTC (link)
	im wondering do you have closest 50 friends, stuff like that? (Reply to this)

	spoiled_sk8ter 2003-08-24 12:29 pm UTC (link)
	I know this might be a stupid question, but how do I get it on my Livejournal entry? (Reply to this)(Thread)

	6waysfromsunday 2003-08-25 05:43 pm UTC (link)
	dont worry i was going to ask the same thing... (Reply to this)(Parent)(Thread)

shawnsmalley
2003-08-26 02:42 am UTC (link)

The easiest way to do this is just to copy the source code (minus the <HEAD> and <BODY> tags) and just paste it into an entry so you can retain the links to their LiveJournals as well as the nice neat formatting and such.
Just right click on the page with the results and hit "View Source", or select "View Source" from your browser's window. It should open up in Notepad, or something of the sort. Then just select all the text except for the HEAD and BODY tags (be sure to leave out the </BODY></HTML> tags at the bottom), copy it to the clipboard (CTRL+C or APPLE+C) then paste it into your LiveJournal entry (CTRL+V) and post as normal.
Worked for me.
Anyone who hasn't been particularly experienced in the ways of HTML may find it a bit tricky, but I can provide additional assistance if this is unclear.

(Reply to this)(Parent)(Thread)

	6waysfromsunday 2003-08-26 11:48 am UTC (link)
	thanks. (Reply to this)(Parent)

cicichikk
2003-08-26 10:39 pm UTC (link)

yes but... the form action is wrong in the output source of the script html.

it says "/trustflow/trustflow.pl?user=username" but that ends up taking people to a 404 page on lj...

so in the form action, it's necessary to put the host of the perl script as the source... unless you want all your friends going 'hey that thing you put up doesn't work at all'.

apparently the host is http://www.gothboffs.co.uk so it'd be action="http://www.gothboffs.co.uk/trustflow/trustflow.pl"... or at least, that's what worked in mine for another friend's 50.

(Reply to this)(Parent)

	stephanielynch 2003-08-29 07:58 am UTC (link)
	Thanks. This was an intriguing exercise particularly since I just had an LJ hissy fit and dumped my 107 friends. lol. Then I added back 18 of them. (Can you say off my meds? snort) So it was very interesting to see who was on my trust flow! Danke! (Reply to this)

	ryb 2003-08-30 03:13 pm UTC (link)
	Фигня! (Reply to this)

	lilychld 2003-08-31 10:04 pm UTC (link)
	Helppp.... (Reply to this)

	alexg 2003-09-03 12:31 pm UTC (link)
	I think you should list the amount of water, or tokens, or whatever unit you're using, after each name - it'd clear up some confusion, and be rather interesting to me at least ^^ (Reply to this)(Thread)

	ciphergoth 2003-09-03 02:26 pm UTC (link)
	Yup, this is planned for the next version, and as you say it's pretty interesting. The next version is pretty cool in many ways - I'm just sorting out hosting now. (Reply to this)(Parent)(Thread)

	alexg 2003-09-03 08:23 pm UTC (link)
	okay, cool ^^ (Reply to this)(Parent)

twiztidpink
2003-09-03 01:58 pm UTC (link)

Something that might help others:
I kept getting the "user not found/no defined friends" error. Tried it several times weeks apart and then today a light bulb went on in my head...

In my user info I had previously marked my friends list as "hidden".

It's pretty obvious now that the script can't find friends that no one else is supposed to know you have. ;)

Now that my blonde is showing, I have reset my settings so that my friends list is visible and I will try back later to see if the tool worked.

(Reply to this)(Thread)

	ciphergoth 2003-09-03 02:29 pm UTC (link)
	This isn't the reason. Actually, I don't know why it's failing for you! Investigating now. You can't hide your "Friends" list, only your "Friends of" list. But TrustFlow doesn't care about your "Friends of" list, only your "Friends" list. (Reply to this)(Parent)(Thread)

	twiztidpink 2003-09-03 03:05 pm UTC (link)
	Gotcha. I assumed it worked off of both lists. It is working for me now. Thank you!! (Reply to this)(Parent)

	ciphergoth 2003-09-03 02:55 pm UTC (link)
	Fixed now. (Reply to this)(Parent)

	matsuei 2003-09-05 02:51 pm UTC (link)
	I finally /didn't/ get the overloaded message (after trying a half dozen or so times over a few weeks), and ended up getting this message instead: TrustFlow for LiveJournal Note: previous attempt to fetch info for matsuei failed. 403 Forbidden, died at /home/www/docs/trustflow/trustflow.pl line 276. (Reply to this)(Thread)

	meow9th 2003-09-05 09:37 pm UTC (link)
	i got that too! what's up with that? (Reply to this)(Parent)

	kwhoissuper 2003-09-06 12:06 am UTC (link)
	failed. 403 Forbidden, died at /home/www/docs/trustflow/trustflow.pl line 276. (Reply to this)

	erincore 2003-09-06 12:50 am UTC (link)
	i got the same message ^^ (Reply to this)

	plain 2003-09-09 06:54 am UTC (link)
	the link is dead can i not use it anymore? (Reply to this)

	juhgu 2005-11-22 12:16 am UTC (link)
	Is this still online somewhere? (Reply to this)

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