[ via Vonda McIntyre ] Ursula K. Le Guin wrote a great essay (Hey Librarians!) on the contradictions caused by shelving fiction by genre:
Not only is this practice [genrification-by-shelving] incredibly invidious, randomly including some genres with the Real Books and excluding others, but it’s also shamelessly inconsistent: the librarians admit that they use personal evaluation of the quality of the book in deciding where to shelve it. Tolkien is famous, so Tolkien gets shelved with Realism. But almost no sf gets deghettoised this way, because few librarians read enough sf or fantasy or know enough about it to pick out the books of “genuine literary value” from the commercial schlock.
Le Guin suggests a metadata approach around the problem of pointing readers at the books they want:
Segregated shelving helps addicts find their fix. But couldn’t its convenience to readers in libraries be replaced by really good lists for addicts? Lists describe and make accessible without evaluating. Our library has a wonderful Readers Advisory Binder at the desk at Central, listing all the popular genres and others I never would have thought of, such as Baseball novels — Thrillers divided into Spy, Legal, Techno and Apocalyptic — Bestsellers. Romance has 7 subcategories: Family saga, Gothic, Historical, Light, Period, Suspense, and Regency. I looked in vain for Bodice-Rippers. My two favorite subgenres were Novels about Older Women and Younger Men, and Seriously Humorous Mysteries.