The Toolbar PageRank value only indicates that a page is in a certain range of the overall scale. One PR=5 page could be just above the PR=5 division and another PR=5 page could be just below the PR=6 division, which is a vast gulf.
Although the exact logarithmic base used for PageRank is a secret, the following table should give you an idea of how different Toolbar PR is from actual PR.
Toolbar PR ------- Actual PR ------------- Actual PR
(linear) (log base 5) (log base 10)
0-----------------------0.15----------------------0.15
0-1--------------------0.15-1--------------------0.15-1
1-2--------------------1-5-----------------------1-10
2-3--------------------5-25---------------------10-100
3-4--------------------25-125------------------100-1000
4-5--------------------125-625----------------1000-10000
5-6--------------------625-3125--------------10000-100000
6-7--------------------3125-15625-----------100000-1000000
7-8--------------------15625-78125---------1000000-10000000
8-9--------------------78125-390625-------10000000-100000000
9-10------------------390625 +-------------100000000 +
This means that moving a page from a PR = 6 to a PR = 7 is much harder than moving from a PR = 4 to a PR = 5.
Although PageRank is assigned per page, your site is a collection of web pages under a domain that you control and hence your site has a total PR value too.
PR as viewed using the Toolbar can be pretty inaccurate. Sometimes home pages for sites will suddenly show a PR = 0 (no green bar) when indeed the page does have a PR value. Appending /index.html to the URL (or whatever the filename is for the home page) in your browser restores the proper value displayed in the Toolbar.
Also, new web pages that the Toolbar displays a PR value for may not have any real PageRank of their own yet. Rather, the new page is assigned a PR value 1 point below an indexed page on the site, but this is an estimate PageRank that exists only in the Toolbar.
by
Rj
