Udi: “Implicit Kicks Explicit’s Ass”

There’s a great article over at Udi’s Spot on the superiority of collecting metadata implicitly (i.e. through natural user actions):

The massively important, and often overlooked, thing about implicit metadata is that it’s generally trustworthy. It’s like the results of a double-blind scientific study. Explicit metadata on the other hand, while often useful, is always in doubt. It’s like the results of an exit poll during an election. People lie. People are stupid. People are remarkably un-self-aware. Going the explicit route exposes you to all of these problems.

This has huge implications for how the metadata that feeds recommendation engines should be collected.

Some personal news sites seem to understand this (e.g. Google, Antlook, Findory). Others–like Reddit, Netflix, and Digg–don’t get it. These sites require that users rate content up or down (or, in the case of Netflix, on a scale of zero to five stars).

Explicit metadata is not only unreliable (as Udi points out), it’s also sparse. The click tax is very high and many users will simply not rate at all. Sites that are designed this way are throwing out a tremendous amount of implicit information about users did (and did not do) on their site.