This will be a half-day, hands-on workshop covering data modeling primarily in RDF. We hope to bring a diverse group of Code4lib community members together to learn, discuss, and understand the basics of data modeling. This modeling work will be taught in the context of interoperability efforts within the Hydra and Fedora communities, particularly in relationship to the development of the Portland Common Data Model (PCDM). We will discuss how data models use a number of standards, discuss how models are used in the context of software design and development, and walk through the different ways to represent models. We will compare and contrast data modeling with metadata standards/profiles. We will walk through modeling efforts around PCDM and its place in our work with digital objects - but this workshop will not focus on PCDM alone or even primarily (this is not a PCDM or RDF workshop). The workshop is intended to serve as the basis for a second workshop (“Data Modeling 201”), proposed separately for as a half-day afternoon workshop.