Background: Scientific Principles and OpennessIn recent decades, the scientific community has become increasingly aware of the importance of openness-for software (open source), publications (open access), structured data (open knowledge), and data collections in general (Open Data). Here, we focus on the latter aspect. Indeed, publishing data collections under open resources has become routine in modern-day research. In this initial chapter, we elaborate on motivations and conventions for publishing Open Data in linguistics and related areas.The Open Data movement in linguistics-as well as in all areas of study in science, computation, and humanities-draws on three main motivations: (1) responsibility, (2) reproducibility, and (3) reusability.