

Blekko already has a list of domains to block from results - aj700
http://blekko.com/ws/+/topspam

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aaronbrethorst
Wow, I'm seeing tons of false positives. Why on earth is the co-written blog
of a nobel laureate and a 7th circuit appeals court judge making blekko's
bayesian classifier freak out?

#88 - <http://www.becker-posner-blog.com> \- bayes (spam 31.6 > 5.3)

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vaksel
my guess is the fact that it has two dashes, which is almost always indicative
of spammers.

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robinduckett
I'm seeing:

<http://www.deadmau5.com> -> Really, spam?

<http://www.comparethemarket.com> -> Price comparison site with no known
biases in the UK __and __not owned by British Telecommunications, as it is
listed.

Even ONE false positive is enough to make me think this listing is a load of
bullshit. How is geocities' "closing down" page spam?

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JamesDB
A site in the UK that gets a huge amount of traffic and is backed by a large
off-line national advertising campaign. Why has this been banned? Never seen
spam on there, nor have seen them spamming.

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seabee
Don't be fooled, that advertising campaign only used a 'sensible', similarly-
named insurance business to introduce an unusual niche company[1] to the
market. It's a clever ploy, you can read about it in Aleksandr Orlov's book
that came out a month ago.

[1] <http://www.comparethemeerkat.com/>

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chrismealy
They're not passing the "best refrigerator" test yet:

<http://blekko.com/ws/best+refrigerator>

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greglindahl
Did you try adding /reviews ? Sometimes we can deliver better results without
the user doing anything different from what they're used to doing, but not
always.

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benbeltran
Two big problems with automated spam blocking are: false positives and
changing domain names.

For the second one, how often do you revise your blocked links? what if it
changed owner and the new one doesn't provide spam.

For the first one, is even one false positive tolerable? Will you deny someone
presence in your index because you failed? And if so, how do you handle
challenges?

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greglindahl
We don't mark a domain as spam until many of the pages we've seen look spammy.

Our ideal is to recrawl everything every 14 days, but during our launch we
have not been achieving that.

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zitterbewegung
Why is <http://www.deadmau5.com/> marked as spam?? Its obviously not.

~~~
lgeek
It looks like they have a considerable number of false positives. Another
site, jet2.com is the website of a low cost airline; wp-plugins.net is hosting
Wordpress plugins.

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moultano
Maybe looking for numbers in the domain name? It's probably a really good
signal overall.

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greglindahl
* This list is generated by our algorithm, it's the most important sites which our algorithm thinks are spam. The point of making the list public is so that you guys can tell us when we're wrong. Google has a list like this, but they don't show it to anyone. Transparency in action.

Thank you all for pointing out false positives in the list. That is what we
hoped would happen.

* The "nocrawl" sites are human-picked by us. Geocities is on the list because it was a very spammy domain. Even though they've (finally) removed the data, we still have old data indexed, and will remove them from the spam list once all that old data ages out.

* BT is the hosting company for comparethemarket.com

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YooLi
There are quite a few false positives on that list. Also titling sites with
nocrawl as spam is pretty lame. dshield.org is listed as mfa, but there isn't
an adsense ad on it.

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wybo
I have been using Blekko as my primary search-engine for a couple of days now,
and in my experience their search-results are very decent.

Not, maybe in terms of falsely blocked sites, but certainly in terms of having
fewer false positives (e.g. spam/useless pages) in the search results.

Mom & pop users (and even more advanced searchers, such as students looking
for book-reviews, or torrents) might very well forgive them the few false
blocks for this.

Zittrain in his 'The Future of the Internet and How to Stop It' already wrote
about this trade-off in terms of spam being made possible by the generativity
of the internet, and people increasingly preferring controlled environments
over those full of virusses and spam (wonder why apple's locked down devices
are so popular?).

Of course this has big downsides too, and even is bad in my opinion. But
Blekko, by allowing people to create their own slashtags (categories, much
more flexible and quick than Googles domain search) and google/yahoo/bing
always being only one click away, might have arrived at a good middle-
ground...

Imho Blekko might very well be able to beat Google at their own game. Give
them a try, or at least sometimes when google doesn't do it for you, I'd
say...

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biot
_> Not, maybe in terms of falsely blocked sites, but certainly in terms of
having fewer false positives (e.g. spam/useless pages) in the search results._

A false positive is when a good site is mistakenly identified as a spammy
site.

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Misha_B
In spite of the (justified) complains you get about the false positives, I
think that's a great way to go. Unlike with email where missing a message
might be critical, in search I'd rather have even as much as 10-20% false
positives than deal with the spam sites Google delivers.

More in general, concerning the front page search examples: "cure for
headaches" works very well indeed compared to google. However, "global warming
/liberal" is a bit irritating. I understand the rationale behind it, however
there is this slight difference between finding only what one is looking for
and hearing only what one wants to hear. To find anything non-mainstream might
necessitate a technique like this in Google where you otherwise don't see
anything else in the first 50 results... But maybe you can strive to find for
me what's really going on and not merely what's mainstream and politically
correct. Thinking about it, your blocking of domains like Answer.com might be
a great step in that direction anyway.

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eli
Really? I'd rather have spam sites than 20% of my legitimate results missing.

I guess it depends on what you're searching for. "cure for headaches" will
probably be just fine with some missing sites, but "Deadmau5 tour dates" will
definitely be affected by the false positive block on deadmau5.com

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cubicle67
can anyone explain what bayes and mfa mean? I picked the site
<http://www.basemetals.com/> (bayes (spam 8.6 > 5.3)) at random, and although
it won't win any design awards I can't see what the problem with it is. Am I
missing something?

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greglindahl
mfa = Made for Adsense. That means we believe that the domain seems designed
more to show ads than to provide content.

bayes = our Baysian analysis gizmo thinks bad things about this site's
content. Too much Viagra, not enough content. Like all artificially-
intelligent things, it can sometimes be hard to see why it's upset.

~~~
nervechannel
Maybe try using something like a decision tree where the classification steps
are much more obvious.

There are parallelizable implementations out there...

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aj700
Omitting these domains from results is "automated".

 _Managing the list isn't_. It's based partly on how many users report a
domain as being spam. At least that's one of the reasons for inclusion. And
don't bayesian filters, with little data to work with and if newly implemented
always have false positives?

Maybe some are labelling valid stuff as spam out of spite.

When blekko has millions of users labelling stuff as spam instead of very few,
the system will be harder to abuse and the list much better.

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zitterbewegung
From all the comments and what I have noticed it sounds like a good question
is "Is it better to have false positives or false negatives" in the spam
problem. I personally think that its better to have false negatives then
positives and a lot of the comments here seem to reflect that.

~~~
greglindahl
That depends on how many false positives and negatives we have -- you don't
really know how many of either. There are 100 million hosts in our crawl, how
can you estimate if we have a false positive problem from looking at the list
of the top 100 marked spam?

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zitterbewegung
Your right. Would there be a way to get a sample of the database and attempt
to do a test if there are a considerable amount of false positives?

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rumpelstiltskin
If they put johnchow.com on the list, they must be doing something right.

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grok2
I actually only saw johnCOW.com (not CHOW).

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veb
Wouldn't it be better to let people do their own blacklists, and then
incorporate that into their official list _if_ a percentage of people have
that site down as spam?

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Entlin
No, that would actually be an easy system to exploit: create a million
accounts with your competitors in it, watch how the search engine blocks it.

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viraptor
Doesn't include swik.net which is a crap link aggregation / search tag spam -
I'd expect that one to be removed...

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kilian
I wonder why they have both the www and the non-www version in there for
domains?

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shiftpgdn
Google counts them as different websites. It is typically a wise SEO move to
use your .htaccess file to setup a 301 redirect to/from the www. version of
your site.

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coolswan
nice. if I had to guess, in a couple years, google will attempt to acquire
blekko to integrate with their webspam team.

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Rubyred
Wow, the search results are terrible on blekko. I think someone's gone crazy
with the ban hammer.

My suggestion to blekko: look for signals of relevance to determine serps,
instead of flagging every other website as spam.

