Are they considered Mirror Sites?

Query as to what is considered "mirror" site

[RazaTiger]

I am a graphic designer and unwilling seo guy for a communication company who owns several websites. We are currently creating layouts that look different, yet most pages are the same from site to site except that the header and footer includes are different. Are these considered mirror sites?

As an example I use our two flagship sites. Each use the same main body for each page, same database, etc. The differences are in the layout and header and footer files. They now want to do this with about 30 more urls, all with different layouts, but same meat and database. Any input would be greatly appreciated.

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[edited by: tedster at 5:55 pm (utc) on Oct. 3, 2005]

[tedster]

With the little bit of change-up you are doing, these sites will most likely register as duplicates -- so only one version should make the search results. The duplicate algo is complex, but it definitely is focused on text content, not graphics and page templates. From what I can see it takes around 30% unique body text (or more) to get a page seen as "not duplicate."

If you put yourself in Google's position, you can see how they wouldn't want their end user to be given a page full of "choices" that were no choice at all in reality.

[mrMister]

No, your sites are not mirrors. Mirrors are identical sites. Your sites all contain "duplicate content".