Inspired by Napoleon Wilson's post on the M&TV Meta, I thought I'd look at some of the statistics on identification questions.
A few notes before I get started:
I don't want to diminish anyone's experience. All of the numbers and graphs and I'm going to spit at you all in this answer are averages. There are certainly some exceptional users who were drawn here by ID questions, or who stay here because of ID questions. I think that's wonderful. Your personal experiences may not match with the average, but that's why averages are average
We're more than just story-id. But not much more; we have seven (non-aliased) identification tags: story-identification, character-identification, episode-identification, author-identification, actor-identification, object-identification, and music-identification, but only story-id has more than 100 questions
Caching is (still) a problem. I'm going to use SEDE as much as possible, so my numbers may be slightly out of date. At time of writing, SEDE was last updated four days ago.
I'm also going to use another frequently-used tag as a baseline; harry-potter is our second most-used tag, so that'll do.
There are currently 5,403 non-deleted ID questions, and 2,677 Harry Potter questions out of 25,574 non-deleted total questions. So 21.1% of all non-deleted questions have been identification questions, and 10.5% have been Harry Potter questions.
Of those ID questions, 287 of them have been closed; that's 5.3% of all ID questions. In accordance with our policy of closing duplicate ID questions, the vast majority of those closures are duplicates; I can't check this with SEDE (or, I don't know how to), but from looking on the main site: out of 293 closed ID questions (coming from a later time), 210 (71.7%) of them were closed as duplicates. With 2,191 total closed questions, ID questions represent 13.1% of all closures.
Of the Harry Potter questions, 328 have been closed, 12.3% of all HP questions; that's 15% of all closed questions. Out of 331 closed questions, 276 (83.4%) of them were closed as duplicates.
Unfortunately I can't comment on deleted questions; SEDE strips tags from deleted questions, and I don't have the mod power to search for them on the main site. Undoubtedly some of the poorer examples get sucked by the roomba, and are lost to my stats.
With the acknowledgement that quality is a hard thing to measure statistically, ID questions are lower in all stats we can measure (note that these are averages, and only includes positive-scoring answers):
I think the average views/question is the number that shocks me the most; ID questions are viewed an average of five times less than non-ID questions. But, though it's less dramatic, I also find it noteworthy that both the questions and their answers are scored noticeably lower than non-ID questions.
ID questions are growing quite rapidly; the left graph shows absolute number of questions (Yellow is total, green is non-ID, blue is ID, red is HP), and the right shows growth as a percentage of total questions (yellow is ID, blue is HP):
Who asks them?
75% of all ID questions are a user's first question, compared with 20.9% of HP questions. When considering only a user's first post, those drop to 71.1% and 16.2%, respectively.
Of all first posts, 26.9% of them are ID posts; when a first post is a question, 50.1% of the time it's an ID question, and when the first post is an answer, it's an ID answer just 10.8% of the time.
In contrast, 8.3% of first posts are HP posts; 5.5% of first-post questions, and 10.2% of first-post answers.
So ID questions are clearly driving new users to the site.
But they're not staying, at least not in droves (red are users whose first question wasn't an ID question; green is for HP, yellow for all askers, blue for ID):
31.1% of users whose first question was an ID question were still visiting 30 days later. Compare to 47.7% for the site average, 59.1% for HP askers, and 63.8% for general non-ID askers.
20.2% of users whose first question was an ID question have any more posts. 16.8% have another post that's not an ID question. Compare to 55.5% and 55.3% for HP-askers, or 34.2% and 32.3% for the site as a whole. Users whose first question is an ID question appear to participate less, in general.
So obviously I have some statements about the utility and quality of ID questions peppered throughout my analysis above. But despite how I may have interpreted the numbers, I don't see ID questions as a problem.
It's true that they've "overtaken" the site, in the sense that they tend to be of less-high quality and utility, as judged by question score and view count, and are abandoned more often (judged by likelihood of acceptance).
But I don't think that's a bad thing for the site. The fact that my numbers are as positive as they are proves that we've been able to stem the tide of really objectionable ID questions (and objectionable questions of all sorts). As long as the ones that are left don't diminish the quality of the site (and they don't; they just increase it by a smaller amount), I have no problem with them.
Likewise, I don't think it's a problem that a third of ID askers keep visiting the site, and that 15-25% of them continue to contribute. I'd rather have those people here, and contributing, then not have them.
At best they're the reason some people keep coming back to the site. At worst, they're a mild nuisance to some frequent users. Yes, I count myself in the "nuisance" group, but the minor inconvenience they cause me is outweighed, in my mind, by the benefit they bring to other users.