Overview NSDL Collection Representation and Information Flow

The intent of this document is to be a brief overview of the current state of collections and associated processing/representation in the NDR. The hope is to convey a general understanding of the current collections architecture as it stands, as well as any advantages, limitations, and not-so-obvious design decisions that were made. It seems appropriate to start by explaining how data in collections currently gets out of the NDR and available to searches before delving further into modeling details.