Tagging doesn't work because there is an incentive to falsely tag to sell stuff. Tag sites with ads for cat products as "dog", "bird", "groceries", "boots", "cars" on the off chance that you'll get your ad for cat products in front of some random customer's eye balls.
It's exactly the same incentive as spam email. It takes zero effort, costs nothing, and if you get 1 hit in a million you still make a profit.
You can see this issue in play easily on soundcloud where people will tag their music with whatever tags they think will get their tracks played. You can also see it on all the porn sites where people re-upload porn with ads inserted or overlayed for their pay-for-porn site and then tag the porn with whatever they think will get click throughs.
you might claim with enough tags you'll be able to tell the accurate tags from the inaccurate tags but I've seen no evidence that that actually works. My guess is it's partly that the only people who have an incentive to tag are the content creators (or content re-uploaders) and they have no incentive to follow any rules.
Further, Agreeing on tags is nearly impossible. Consider "man" vs "woman" and all the political discussion around that. There's a conflict between those that want the tag for their identity, and those that want the tag to be useful for filtering. As much as I respect people's identities it's more useful for filtering if I can search for "brunette" and only see brunettes. And, if you find some other tag to use for the filtering then it's only a matter of time before someone demands they be identified with that new tag.
It's exactly the same incentive as spam email. It takes zero effort, costs nothing, and if you get 1 hit in a million you still make a profit.
You can see this issue in play easily on soundcloud where people will tag their music with whatever tags they think will get their tracks played. You can also see it on all the porn sites where people re-upload porn with ads inserted or overlayed for their pay-for-porn site and then tag the porn with whatever they think will get click throughs.
you might claim with enough tags you'll be able to tell the accurate tags from the inaccurate tags but I've seen no evidence that that actually works. My guess is it's partly that the only people who have an incentive to tag are the content creators (or content re-uploaders) and they have no incentive to follow any rules.
Further, Agreeing on tags is nearly impossible. Consider "man" vs "woman" and all the political discussion around that. There's a conflict between those that want the tag for their identity, and those that want the tag to be useful for filtering. As much as I respect people's identities it's more useful for filtering if I can search for "brunette" and only see brunettes. And, if you find some other tag to use for the filtering then it's only a matter of time before someone demands they be identified with that new tag.