How reliable are rating systems for media? It depends on what you're looking for.

Cheri and Kayla both wrote posts on the potential for a book rating system, similar to movies and video games. I've considered this concept before, but one thing that I think is interesting about rating systems is the tendency for them to lose meaning over time. As society changes, what is appropriate for certain audiences changes as well. For example, a PG-13 rating for a movie now allows for more explicit content than a PG-13 movie from 15 years ago. The Motion Picture Association of America explains this on their website under Ratings History, "As American parents' sensitivities change, so too does the rating system. Elements such as violence, language, drug use, and sexuality are continually re-evaluated through surveys and focus groups to mirror contemporary concern and to better assist parents in making the right viewing choices."

This approach is perfectly reasonable if you don't have fixed opinions about appropriateness based on what you think are absolute truths. If your opinions are based on relative truths subject to change and influenced by the greater opinion of society at large, then this system probably works for you, if you agree with the direction society at large is traveling in concerning media. But if you are someone in the absolute truth category and the ratings system doesn't reflect those absolute truths, then the system loses meaning for you.

For example, it is apparently not a contemporary concern if 13-year old children hear the F word twice in a PG-13 movie because that is considered acceptable content for a movie of that rating. I don't think this is appropriate for a 13-year old. I understand that many 13-year olds hear that kind of language walking through a school hallway five time a week; nevertheless, I don't see a reason to put that language in a movie that is rated as appropriate for 13-year olds.

To get back to the discussion on a rating system for books, I think a rating system for books could be useful. However, I assume such a rating system would be similar to the MPAA's rating system, and that means the system would be subject to constant change based on the opinions of contemporary parents and their concerns, which of course probably will not match up with my concerns. Don't get me wrong, I think the idea of parents evaluating media on a semi-regular basis is generally good. I just think that rating systems are always a product of a society's values at a given time, and because they change, they are not very effective.

What do you think? Would a rating system for books be patterned after a rating system for movies? Should there be different independent rating systems: a national one and others run by groups of parents with more specific concerns? As mentioned by a commenter in one of the other blogs on this subject, how would a ratings system restrict children from reading books worth their while that do have some more mature content?