Balisage Paper: Four Basic Building Principles (Patterns) for XML Schemas

Practitioners have long identified four distinct patterns for construction of XSD schemas, known by the picturesque names “Salami Slice”, “Venetian Blind”, “Russian Doll”, and “Garden of Eden”, and based on two binary choices: are all the element declarations global? or (apart from the intended document root) local? Are all the type definitions global? Or (apart from the built-in types) local? Informal discussions often focus on the effect of pattern choice for schema re-use, encapsulation, coupling, and cohesion. But a more formal approach is needed to determine whether choice of pattern affects the languages we can define with the schemas we can write.