From Jenn Riley’s Sunday posting, The next big thing in searching?:
Discussions of FRBR displays frequently talk about presenting Expressions with a language for textual items, with a director for film, or with a performer for music, allowing users to select the Expression most useful to them before viewing Manifestations. What’s missing is how the system knows what bits of information would be relevant for distinguishing between Expressions, since these bits of information will be different for different types of materials, and sometimes even with similar types of materials. We have a ways to go before the type of system I’m imagining reaches maturity.