doc_z - 9:57 am on Oct 8, 2004 (gmt 0)

Do you see inconsistencies in toolbar PR with older pages with older links?

Yes, the pages (and the linking structure) are at least six months old - some are unchanged for more than a year.

what inconsistencies do you see?

There are several types of inconsistencies. Two examples (the are even more):
- an increase of PR where a decease should occur (this is a fundamental problem)
- two identical structures which must have the same PR (same linking structure and identical incoming PR) have different PR

so what if google was showing pr that is two / three months old...

This wouldn’t explain the behaviour described above.

My guess is that Google is now using age of page or age of link as a factor in calculating PageRank.

Talking the age for PR calculation (!) into account wouldn’t make sense (and it would be complicate and time consuming to get a valid model) and wouldn’t explain my data (at least there must be also other changes).

These newer (but June/July) pages seem to have lower PR than parallel pages...

all pages linked from the homepage gained PR for the first time and range from PR1 - PR3.

Newer pages linked to from a central indexed page have about 1 less page rank than older pages

HOWEVER, that news report from 19 September has only a PR3. This is way below what should be expected.

I had some older stuff that should have gone to a PR 6 or 7 that stayed constant at a 5. However I had some new stuff that that ended up right on target at a PR4.

As said, a age factor can’t explain all my data. However, I’m also seeing this effect for several pages/sites!

I would guess that this isn’t a results from additional factors introduced into the PR formular but a side effect resulting from the new kind of PR calculation, i.e. they didn’t changed the PR formula but the calculation (iteration scheme) which leads to this (unwanted?) effect.

There are actually no special reason to calculate PR all at once as it seems was before.

Of course, there is a reason to calculate PR at once: PR cannot be calculated accurate locally.

What if Google decided to do only a few iterations (maybe 10 or so) but started the value at the previous PR value.

Yes, starting with the values of the last calculation makes sense and speeds up the calculation (we discussed this before, e.g. here [webmasterworld.com]). And perhaps this is part of the explanation. However, in most a the cases people described here even one iteration should give a result (for new pages which are directly linked from an old page) which is close to the exact value (especially if we are talking about the toolbar, because this is a logarithmic scale). More iterations are mainly necessary for deeper inner pages (propagation).

It may be change in the algorithm. It looks reasonable that a collection of good relevant outbound links should have some authority, i.e. a little PR.

I’m talking about the PR algorithm not the ranking algorithm.

After all, PR algorithm was a student work of Google founders and they may change it easily and without a warning.

They already made changes long time ago. However, there are some general principles which shouldn’t be violated even if details where changed (see the examples given at the beginning).