So I'm going to ramble about my experience with tags on two sites so far. TL,DR: yeah, probably.
First, I see two and a half uses for tags:
- People who're interested in answering (or more generally seeing questions) about certain topics can ignore or favorite certain tags.
- People who're searching for something can narrow their search.
- Tag wikis (but do people actually read them)?
Most tags are names of applications or technologies. They're what people naturally use when they want help on a particular technology, which is what most questions are about. A question about using KDE? tag it kde. Some of these tags have lots of questions (for example linux is the biggest tag by far), others have very few (sco isn't exactly popular), but it's pretty clear that these are desirable tags. There's the occasional name coincidence hurdle (e.g. is ports about TCP or BSD?) but nothing we can't easily solve on a case by case basis.
Then there are topic tags, such as security or networking. Those have mostly arisen naturally as well. They're what people tend to use when they want to do something but don't know what the right tool is. I'm still sometimes undecided as to how precise to go; for example networking is pretty wide, and I'm still undecided as to whether it should be used when more specific tags apply (firewall, ethernet, …).
Sometimes the distinction between tags is subtle. For example, what's the difference between shell, command-line and terminal? Beginners will often use shell and terminal indiscriminately, but at the level of U&L, we do want to make the difference (shell is our second-biggest tag, and bash (a kind of shell) is close behind). Since the difference useful but subtle, we don't expect askers to always get it right. In general, though, I don't know where to stop caring about differences that are only apparent to experts (should x11 be separate from xorg? packaging from package-management?).
Hyphenated tags — tags about a frequent combination of two distinct concepts — arise rarely, but in high-profile topics. Should Linux kernel questions be tagged linux-kernel or linux kernel? (we settled on two tags). Should shell scripting questions have their own shell-script tag, or do we combine shell and scripting (you can shell without a script and script without a shell, so they're not synonyms in any way)? we haven't been able to make up our mind.
Meta-tags haven't been a problem. There are borderline cases, like software-rec, which characterizes the nature of a question rather than its topic (but I find it useful: it marks the nature of a question succinctly in search results or in a feed). And each site seems doomed to have its own debate about homework. But no major issue there.
All in all, tagging for Unix seems to have worked reasonably well, with just a few hurdles.
Most questions are about a specific work, author or universe. And most of these questions have just one tag: the name of the work/author/universe. Sometimes with variants such as lotr j-r-r-tolkien. We're still undecided as to whether that's generally useful: after all, the name should be in the body and so the question will turn up in searches anyway. For popular works, and especially universes spanning multiple works, these tags are useful (a star-wars question might only contain the name of one of the movies in the series, and that's a tag fans subscribe to). But at the other end of the spectrum, who's going to subscribe to <obscure author name>?
These names tend to lead to near-synonyms that aren't actually synonyms. Discworld is Terry Pratchett's best-known work,
so I expect most questions about him will be tagged discworld. Does that mean terry-pratchett should be used on all Discworld questions? or only on non-Discworld questions? We haven't yet had enough volume in a tag to need to decide.
We've just started to encourage topic tags. If your question is about spaceships in Star Trek, tag it star-trek spaceship. I hope it'll catch on. That would leave only questions about specific plot points or characters tagged solely with a work or author name.
It's been suggested to use subgenres as tag names — similar to English Language & Usage's broad tags (word-choice, verbs, …), I suppose. We practically haven't been doing that. I think the reason is that subgenre classification is awfully vague and subjective. Can tags still work if people don't agree on what they cover? Are subgenre names meta-tags for us?
Or is the proper analogy with EL&U to use tags like character, plot and setting? While these are objective, I don't see what value they bring to our site. Is it really useful to quickly sort between Harry Potter character questions and Harry Potter setting questions?
We have a couple of meta tags. The ones that remain are list and recommendation, both marking types of questions that have been rules off-topic and are all closed (and that we might delete en masse at some point).
I don't feel we've settled on good tagging practices for SF&F.
Conclusion
I find it interesting that Patrick McElhaney's experience on UX is pretty different from mine, and mine is different on U&L and on SF&F. My impression so far is that different communities face different problems when choosing tags. So, can you, gentle reader, find common patterns and come forth with good advice?
