Could Google be updating PR one site at a time?

[derrickcm]

I operate several content web sites, and I have noticed over the last couple of months some of the PR0 web sites have been given a PR1 or PR2 although I cannot see any news of an official PR update, and also some other content sites I have where i was expecting a rise have not changed yet.

Has anybody else noticed this? Is it possible that they are updating PR for some sites 1 at a time? If not, is there an explanation for this? Maybe this is common knowledge and I just have not heard of it before? I would like to know your thoughts on this.

[tedster]

People do report seeing PR change in between the more global PR updates. It's never been discussed much, except to note that it does happen. We can guess why it happens (Google found and fixed a data export bug, or removed toolbar PR penalty, or whatever) but I've never seen an official comment about it, so I'd just be building castles in the sand if I said much more.

[edited by: tedster at 2:25 pm (utc) on June 26, 2008]

[rustybrick]

Matt Cutts has said that they do exports of PR scores to the toolbar every 3 or 4 months. So I am not sure about this. Yes, we do see tons of people saying there is a PR update for their site between those dates. So like tedster, I am not sure.