Duplicate content filter

At which point does the filter get applied?

[Essex_boy]

If I have 10% duplicate content, for example reprints of famous interviews with sports stars, would the filter be applied?

or does your duplicate content level have to be much higher say over 50%?

[glitterball]

Could it be that the dupe content filter is being applied only to new sites?

My MIA site was started in 2002, so I don't think that this is a penalty only applied to new sites (though maybe 2002 is new to Google, it is to DMOZ).

However, I have a second site that is not indexed at all. I recently changed the domain name of this relatively new site, but Google does not seem to want to index it (Google states that it has no information about this domain).

When I made the changeover to the new domain (on another server), I made the mistake of using a temporary redirect - which I later changed to a 301.
At first (with the temporary redirect), Google continued to list the old domain name, but with the Title and Decsription taken from the new website.
Later, when I updated the redirect to a 301, the site dropped out of Google completely and has not appeared since.

Without going into details, the website in question provides a service based around a new technology. At present there isn't even a competitor. I have managed to receive many non-reciprocal links from most of this industries' community and media websites - I don't even have a links page.

I think that we can safely narrow this 'Bug' introduced by Allegra to be related to redirects and duplicate content. I believe that I am just seeing the side-effects of this update on two of my sites.

[webtress]

webtress, if pages that are too similar are placed in the supplemental index, then why would my home page--which has zero duplicate content--also be in the supplementals? In fact, every single page on my site is in the supplemental index, similar content or not.

I am not saying the duplicate content is the only way to wind up in the supplemental hole but that it is one of the ways.

[walkman]

if in G's eyes you have dupe content, wouldn't those pages (or entire site) be under supplemental or filtered via &filter=0?

What do you guys think?

[dickbaker]

walkman, as I've mentioned before, I have roughly 1,000 pages of individual models from various manufacturers on my site. I use the manufacturers' descriptions of their products on those pages.

If I copy the first paragraph or so from any one of the product descriptions and paste it into Google's search box, I get all sorts of sites that are using the same descriptions. Many of these sites rank in the top ten for searches for the models by name.

On the other hand, what you just described--a site being under the &filter=0--is exactly where my entire site is.

If dupe content is the cause, then Google is being very selective in choosing which sites stay at the top and which get the 0 filter.