That's why you don't let users invent tags of their own but enforce a unified premade dictionary.
Then it's still hard to make sure people use them properly and consistently; even with admin-specified tags, those tags can be applied inconsistently by post authors such as to deflate the specificity of the tags or shift their meaning.
Also I know at least one website which lets people with sufficiently high karma retag posts of others -- that should be helpful with fixing problems.
I think maybe the reason Luke is specifically suggesting changing the subreddit partition is because this requires a one-off, upfront, unusually small (compared to other LW improvements) investment of time. High-karma folk (re)tagging is riskier because it puts an ongoing burden on a small number of people, introduces more opportunity for drama and disruptive disagreement, and very probably introduces other issues.
it's still hard to make sure people use them properly and consistently
Isn't that risk equally present with subreddits (i.e., people choosing the wrong subreddit)?
Less Wrong is based on reddit code, which means we can create subreddits with relative ease.
Right now we have two subreddits, Main and Discussion. These are distinguished not by subject matter, but by whether a post is the type of thing that might be promoted to the front page or not (e.g. a meetup announcement, or a particularly well-composed and useful post).
As a result, almost everything is published to Discussion, and thus it is difficult for busy people to follow only the subjects they care about. More people will be able to engage if we split things into topic-specific subreddits, and make it easy to follow only what they care about.
To make it easier for people to follow only what they care about, we're building the code for a Dashboard thingie.
But we also need to figure out which subreddits to create, and we'd like community feedback about that.
We'll probably start small, with just 1-5 new subreddits.
Below are some initial ideas, to get the conversation started.
Idea 1
Idea 2