Working through the screen scraping for Mivvi’s data, I found that HBO.com’s redesign had, as well as breaking a number of links and making heavy use of Flash (Flash? Flash.) lost any mention of a few old shows: Deadwood, Carnivàle and Rome. This is a real shame. Their site had been doing a great job of providing real content, per-episode pages and extra context, and losing that history misses an opportunity to remain an authoritative long-term source.
As the W3’s oft-quoted “Cool URIs don’t change“ says, “When someone follows a link and it breaks, they generally lose confidence in the owner of the server.”
The Open Graph Protocol aims to promote exactly those kinds of long-lived definitive URIs for concepts: films, sports teams and many more. (The IMDb‘s involvement isn’t a surprise — they’ve kept their status as de facto custodians of film identifiers for as long as I can remember.)
So, when I need a stable identifier for those shows, who do I go to? I can’t see a better source than Wikipedia. I trust them to be stable, or at least to redirect, and I trust the content that’s at the end. Not HBO, for an HBO series; again, a missed opportunity.
RDF accepts that resource identifiers may change, or need to be unified, and allows the owl:sameAs predicate to declare that A and B represent the same thing (as supported by sameas.org). It’s a great tool for migration and merging, which is especially powerful when you realise that URIs don’t need to be resolved when they’re used as identifiers. (Although it’s better when they can be!)