In an interview with Wired magazines Steven Levy, titled ""Panda" That Hates Farms", Googlers Amit Singhal and Matt Cutts speak more about the recent Farmer ranking algorithm update.
Cutts and Singhal reveal that Google calls the update "Panda" internally, named after a Google engineer.
They revealed that last year's launch of the "Caffeine" indexing infrastructure played a role in upping the visibility of "shallow content."
[Amit Singhal speaking] Our index grew so quickly, and we were just crawling at a much faster speed. When that happened, we basically got a lot of good fresh content, and some not so good. The problem had shifted from random gibberish, which the spam team had nicely taken care of, into somewhat more like written prose. But the content was shallow.
Singhal said the shallow content overload that had users complaining mostly came about due to their Caffeine update. But Google still is having trouble defining "low quality" - with Singhal saying Google still hasn't solved it.
Cutts said Google "came up with a classifier to say, okay, IRS or Wikipedia or New York Times is over on this side, and the low-quality sites are over on this side. And you can really see mathematical reasons."
"Our classifier that we built this time does a very good job of finding low-quality sites," Singhal added. "It was more cautious with mixed-quality sites, because caution is important."
So big brands seem safe in Google's eyes -- potentially more bad news for the little guy on Google. Cutts also mentioned government sites ranking higher for medical searches.
Another hint if you want to figure out what not to do, according to Cutts: Look at Suite 101. Go there, look around, figure out what they're doing, and make sure you're doing the opposite.
Make Google Trust Your Site
How does Google determine this? It seems Google is using outside human raters, at least in part, as a form of quality assurance. Singhal said they asked raters questions like "Would you be comfortable giving this site your credit card? Would you be comfortable giving medicine prescribed by this site to your kids?"
Cutts said other questions Google asked to establish trust include "Do you consider this site to be authoritative? Would it be okay if this was in a magazine? Does this site have excessive ads?"
Some SEOs are interpreting this to mean sites overloaded with AdSense and others advertisements are now in Google's crosshairs.
Google has also previously mentioned that Google's Chrome site blocker extension could become a ranking signal. In rolling out the Panda update, Google said the spammy sites reported by Chrome users wasn't used, but it was used for comparative purposes. Google reported an 84% overlap with blocked and downgraded sites.
Some SEOs are speculating that Google may be looking at the ratio of above-the-fold content (word count) to advertising. Many of the sites punished by Google had more ads than useful content.
Full Interview On: Wired.com