Google News

Google News

Google Further Clarifies Nofollow and PageRank Sculpting

Earlier this month, Matt Cutts shared with search marketers that Google had begun treating nofollow differently, especially in regards to "PageRank sculpting," the advanced SEO tactic that aims to control where PageRank flows around a site.

Today, he goes into detail on how Google views PageRank sculpting, and how it treats the nofollow attribute in regards to PageRank flow.

Cutts offers a simplified description of the PageRank process, where a page's value flows out to the various pages it links to equally. When the nofollow attribute originally came on the scene, Google would just remove those links from the equation, according to Cutts. So if a page with 10 "PageRank points" to share had ten links on it, and five were nofollowed, each regular link would pass two PageRank points.

Cutts today said that Google changed this practice more than a year ago to keep the nofollowed links in the equation, but not passing any PageRank points. So in that same example, the regular links would each pass 1 PageRank point, and the nofollowed links would still "use up" their allotted points, even though they did not pass those points on.

Block or remove pages using a robots.txt file

Block or remove pages using a robots.txt file

A robots.txt file restricts access to your site by search engine robots that crawl the web. These bots are automated, and before they access pages of a site, they check to see if a robots.txt file exists that prevents them from accessing certain pages. (All respectable robots will respect the directives in a robots.txt file, although some may interpret them differently. However, a robots.txt is not enforceable, and some spammers and other troublemakers may ignore it. For this reason, we recommend password protecting confidential information.)

You need a robots.txt file only if your site includes content that you don't want search engines to index. If you want search engines to index everything in your site, you don't need a robots.txt file (not even an empty one).

While Google won't crawl or index the content of pages blocked by robots.txt, we may still index the URLs if we find them on other pages on the web. As a result, the URL of the page and, potentially, other publicly available information such as anchor text in links to the site, or the title from the Open Directory Project (www.dmoz.org), can appear in Google search results.

In order to use a robots.txt file, you'll need to have access to the root of your domain (if you're not sure, check with your web hoster). If you don't have access to the root of a domain, you can restrict access using the robots meta tag.

For More Info: http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=156449