how google panda update has affected websites?

[SENtelligence]

There are a lot of speculations regarding Panda on the Internet, but most of them are not based on anything material. I'd advice you to read this wikipedia page about the Panda update first.

Google has never disclosed what actually triggers the algorithm, they've only hinted at what sites'd be safe from it, so, SEO's went on speculating and suggesting that, perhaps, Google is now looking at how unique your content is, how high your CTR (from the SERPs) is, other user-behavior metrics (time on site, etc.)

However, the only thing we know for a fact is that Google had let their quality testers look at tons of websites, and then, a machine-learning algorithm was used to analyze what the "downvoted" sites had in common, which lay the foundation for the Panda update.

[richardfranklin]

By having Panda update, Google decided to reward those websites, which have high quality unique content on their websites. Through this updates the websites which were not providing useful and relevant information to their users, have been penalized.

[richardfranklin]

Panda is a reward to those websites which have high quality unique content on their websites and a penalty to those which have copied it from other resources or having less useful information for users.

[SENtelligence]

By having Panda update, Google decided to reward those websites, which have high quality unique content on their websites. Through this updates the websites which were not providing useful and relevant information to their users, have been penalized.

Even though what you're saying does sound a bit pompous and idealistic, I have to admit that Panda did quite a good job, and most of the sites complaining on webmaster central are indeed crappy (and sometimes creepy). However, ever since Panda hit, the amount of web spam has scaled up too.

[LD]

I look at it like this. What may seem like a reward for some sites in terms of SERPs, can be looked at as more of a byproduct of the devaluation of lower value sites. When sites are repositioned lower in the SERPs due to devaluation, the previously lower positioned sites that add value in their existence, would move up.

[ozsubasi]

How it will find duplicate content?

I can find duplicate content easily enough - just type an extract into Google search and see what comes up. For specific phrases use " at the beginning and end. If I can do that don't you think Google can?
Have a look at this:
http://support.google.com/webmasters...n&answer=66359

[deepsand]

How they distinguish duplicate contents. Suppose two sites "A" and "B" have same contents, then will A be duplicate of B or vice versa.

No particular copy enjoys an inherent advantage over any and all others.

Google will try to determine which copy, within the context that it is presented, is the better suited for the user's query string.

By analogy, consider the task of selecting which recorded version of a song or other musical work is most likely to be best liked by a particular listener.

[nhunet]

depends on the time google robot fetches content of a website. By this way google can know which content appears first.

[deepsand]

depends on the time google robot fetches content of a website. By this way google can know which content appears first.

Which appears first is not necessarily the original.

And, being the original does not mean that it's the best suited for a particular query string.

Being "first" guarantees nothing.

[ozsubasi]

Which appears first is not necessarily the original.
And, being the original does not mean that it's the best suited for a particular query string.
Being "first" guarantees nothing.

This is something I wasn't really aware of until just now when I came across it when researching something else, and what you are saying seems to confirm it.
I had thought that the first publication would be the original, but hadn't taken into account the matter of indexing. My understanding now is that I could post something original on my site but it may not get indexed for a while, whereas a copy on a site crawled more frequently could have it visible sooner.
If my understanding is correct, how could I then prove mine was the original, if I wanted to report the copy?