Vouching for Weblogs
Dave Winer: I only want changes.xml to have weblogs in it. I want to set up some kind of web app that makes sure that happens. Any thoughts on how to do that?
Those that read my weblog may have detected a passion I have for increasing the connections between things. Today, we have an another opportunity to decrease entropy.
In the comments section, there are a number of good suggestions. Including one for a "smackup". Whereby people are expected to vouch for other people. A system where there is no foes, only friends.
There is prior art for this. It is called Friend Of A Friend, or FOAF for short. It can do much more than what I am about to describe, but lets keep things simple and focus on the problem at hand.
weblogs.com keeps track of existing weblogs for the purposes of detecting if a ping truly represents a change. So lets treat the existing weblogs as known good. Now lets look at what happens when we get a new ping.
If the site identified in the ping is already on the list, then all proceeds normally.
If that site is not on the list, then we need to check further. Even though he is an established blogger, let's take James Snell for example. Fetch his page, and look for <link> tags. When you find one with type="meta" and type="application/rdf+xml", use the href.
Go there and you will find a file. Don't freak, it has some other things that you don't care about at this time. In this case, all we are looking for is rdfs:seeAlso tags. These identify people that James says are his friends. But we can't just take his word for it. We can go there.
The first friend listed happens to be me. Let's go there. This time, we are looking for two things. First we look for a rdfs:seeAlso link back to James Snell to verify the link. Seeing that it is there, we have a level of validation. Now we have to decide whether that is just a shill. So we do one additional validation. We look for a foaf:homepage and see if it is in the list of existing weblog.com websites. If so, we are done.
Simple. Effective. Works with and builds on prior art.
Building a FOAF file is easy. There even is a FOAF-a-matic to help you.