aristotle - 11:08 am on Apr 13, 2011 (gmt 0)

Adding a noindex meta tag to a page's header causes Google to remove the page from its search index. Thus the page will no longer appear in Google's SERPs.

But people can still visit the page, so even though it's no longer indexed, it still contributes content to the site. What I'm wondering is whether this content can affect the rankings of other pages on the site that are still in the index.

In other words, since people can still visit no-indexed pages, does the Google algorithm include them in its evaluation of the overall content and quality of the site?