How much is Pagerank2 + Pagerank2?

[tribal]

With pagerank it's not possible to calculate.. You can't say: "How much is PR2 + PR2".
I once read somewhere(can't find it back) that PR6 is worth 3 times more than PR5, and that PR5 is worth 3 times more than PR4, etc.

Assuming this is true, you could translate pagerank to points:

PR0 = 1 point
PR1 = 3 * 1 point = 3 points
PR2 = 3 * 3 = 9
PR3 = 3 * 9 = 27
PR4 = 3 * 27 = 81
PR5 = 3 * 81 = 243
PR6 = 3 * 243 = 729
etc.

Now you could say that 10 PR4 sites, have the same linkpower as one PR6 site. Because 10 times 81 points is in the PR6 area.

Now i also assume that my little theory above probably isn't true, so i was wondering if someone could give some opninions about the relations between pagerank.. Is multiplying by 3 good, or should it be more ore less?

[arieng]

I'd always thought PR was a base-10 logarithmic scale. If that was the case, PR2 + PR2 = PR2.1.

[tedster]

It is an exponential scale - not quite so steep as log 10. People who have crunched the numbers more intensively than I have say it's in the area of log base 6.

The big deal is that the 11 levels of toolbar PR are not nearly granular enough. Behind the scenes, Google uses a calculation that takes the PR of a url to many decimal places. A PR 2.9999 url would have six times the power of a 2.0001, but on the toolbar they look the same.

[tribal]

I read different things from scale 3 to 10.. But 6 sounds really believable.