how do they rank posts?

Marmite, you can learn about PostRank @ http://postrank.com/postrank.html

You're right, the metrics we consume currently tend to have an US bias. Having said that, we are working on expanding that list to include Europe and Asia in the near future.

The data sources we analyze (metrics) at this point tend to be produced by North American companies and so be sites/services that are popular here, but not necessarily elsewhere in the world.

Other regions and countries have their own version of bookmarking sites, instant messaging sites, social networking, etc., so for interactions from those sites to be included in PostRank analysis, we need to add them.

At this point, though, we're still working on finding out what other popular sites around the world are, and once we know, we can work on adding them.

I *think* that addresses what you were asking, but if not, please let me know.

Rankings are based on the site's performance over time, however, only a subset of time because rankings would lose context if everything was compared to everything else.

The content of a post itself is ranked according to how other people have reacted to it. Using comments as one metric for the example of your site, the Joker post got 2 more comments than the post preceding it, for example, hence the 8 ranking for the Joker post as opposed to the 6 ranking for the one preceding it.

Because rankings are based on engagement over a period of time, but, as noted, a new post isn't compared to every other post you've ever done, the British education post isn't getting compared head to head, exactly, with the Joker post, for example. However, the British education post ranked higher than the post preceding it because it got 1 more comment.

The Toby Young post scored relatively low at 4.2 because the post preceding it got a lot more comments -- 13 more -- and so scored a 9.7.

Really, how you or others feel about your content won't be reflected unless they act on it -- leaving comments, tweeting, delicious bookmarks, diggs, etc. We are quite aware, however, that many of our analysis sources are somewhat North American-centric, and so we're always looking for more international and regional sources, and recommendations thereof as well.

And, of course, if there are engagement sources you know have been used -- tweets, bookmarks, etc., but which aren't being displayed in your rankings, please let me know and we'll look into it.

So what appears to be the case is that your feed URL is recursive -- it's just pointing back to itself instead of to a valid RSS feed, and so is not picking up new posts (and so we can't analyze new posts). For example, if you go to your blog and click on the orange RSS icon in the address bar, then select "Subscribe to 'RSS'", it doesn't go to a feed page, something like this: http://feeds.feedburner.com/aiderss, it just goes back to your blog homepage.

Did you make any big changes to your setup towards the end of September? (The 28th is the last post date in our system.) I'd recommend taking a look at the URL you submitted to Feed Burner and/or what you've entered in your Blogger settings.

Your posts look up to date in our system: http://www.postrank.com/feed/887c6f60... - though the metrics appear to be behind, e.g. we're not showing the 8 comments for your Nov. 5th post yet.

I'll find out whether something's amiss there, or if it'll just take a bit of time for the analysis to get caught up.