If you use the Internet radio station Pandora then you have taken advantage of the Music Genome Project. The properties of songs are analyzed and then you get recommendations based on the properties of songs you've liked in the past. Some of the properties (and they claim that there are hundreds catalogued) for a song I listened to were:
hard rock roots
punk influences
a subtle use of paired vocal harmony
varying tempo and time signatures
What I was thinking was, wouldn't it be cool if anime and manga could be catalogued in a similar way. What are properties that could used to differentiate between different anime or manga? Some of the ones I thought of:
Heavy/light outlines
Heavy/light shadowing
Overall positive/negative message
Ambiguous morality (e.g., a Byronic hero)
Heavy/light/no use of CGI
Realistic portrayal of the human body
I'm curious to see which ones you guys can come up with.