What is interoperability?
Interoperability is creating a system which is compatible with a large number of disparate systems. As people use different software and hardware to access the same information, it is important that the information be accessible to these different devices.
Why is interoperability important for digital libraries?
If a digital library is not widely accessible then a librarian is creating a biased construct, not one which is publicly accessible. If a librarian creates a digital library whcih excludes users, he is not taking the idea of a modern library and transposing it to the digital world, but transposing the idea of a nineteenth century library in the digital world.
What is OAI-PMH?
OAI-PMH is a method for harvesting metadata.
Why is OAI-PMH important for digital libraries?
OAI-PMH provides an excellent model for a digital librarian. It gathers metadata efficiently and metadata is critical to the digital library's functioning.