Jason Calacanis' post on Technorati's top 100, Bob Wyman's response all make for good reading, but Mary Hodder's recent sketch of a ranking system based on a mixture of features trumps them all. Hodder gets back to one of the key issues of the discussion which is: link based ranking is a proxy for influence. This is something that Sifry has always been careful to articulate.
The notion of a proxy for influence is important because it leads to: is it a good proxy? and, is influence really the thing that we are interested in? Wyman's response is interesting in that it offers some great insights into how PubSub think about the various features (a subset of Hodder's features). The notion of decay with respect to the time that a link was created and with respect to the number of links from a single site is as insightful as Hodder's comment that a link in a blogroll now is far more selective than one from last year (when there were fewer blogrolls to deal with).
- A ranking like Technorati's is not as sinister as some make it out - it is what it is and we can take or leave it.
- The user needs that a ranking of blogs satisfy are as numerous as the methods we could use to rank them. Hodder calls for a transparent system, but a system with the number of features that are listed in her post (19) would be transparent but inscrutable.
- Transparency is not independent of simplicity and simplicity can not serve all use cases.
The fundamental problem is that there aren't any good models of the blogosphere that have been adapted to ranking or other sorting problems. In addition, the articulation of the desired function has been lost in the high dimensionality of the things that we could measure or observe. This is why the simple link count is such a great whipping boy - everyone understands it and no-one likes it.
So rather than a complex transparent feature set, I would rather see a number of simple ranking models. For example, blogroll based ranking, site ranking, link ranking, media mention ranking, and so on.
UPDATE: Chip Griffin posts very similar sentiments.