Peter Gabriel adds a wrinkle or two (sorry, couldn't resist)

Actually, despite the somewhat dismissive tone of my last post, there are a couple of interesting wrinkles to The Filter.

First is that it does away with user ratings. It doesn't ask you to give a number of stars or whatever to a selection. Instead, it notes what you do with it. If you keep purchasing something by an artist, it concludes that you must like that artist.

In other words, actions speak louder than words.

The Filter also weights more recent actions more heavily than older ones, sort of a "what have you done for me lately?" approach. Your rave about your favorite boy band is not going to come back and haunt you in your thirties (unless you're still into them and buy the reunion DVD, of course).

Ratings have a couple of theoretical weaknesses. One is how to normalize the scores. I might tend to reserve a five-star rating for that rare near-perfect item, while you might tend to give it to everything you like. Another is that either of our ratings of an item might change after the initial enthusiasm or reluctance wears off, but most of us won't be bothered to change a rating except perhaps in extreme cases. Another is that many of us can rarely be bothered to assign a rating in the first place.

One of the tenets of the whole "wisdom of crowds" approach is that, given enough data points, such discrepancies will tend to even out. Fair enough, but that's true whether the raw data comes from people's recommendations or from their mouse clicks. If ratings are redundant or even inconsistent with more accurate indicators of what people are thinking, then they may well just be in the way.

The only way to know for sure is to try the experiment. Either way The Filter remains a crowd-based service. As far as I can tell you're not getting PG's picks, per se, or anybody's in particular.

I still don't think any of this is particularly novel. As I recall, the various music playing apps track how much you play a song and can infer a rating from it, and weighting recent activity more heavily is an old idea (compare exponential moving averages in technical trading, for example). On the other hand, not everything has to be a breakthrough. Much -- some could argue all -- progress is made by incremental tinkering and trying existing ideas in slightly new combinations.