Rachel Pottinger http://www.cs.washington.edu/homes/rap The Merge Operator in Model Management Systems A model is a complex discrete structure that represents a design artifact, e.g., a database schema, entity-relationship diagram, UML model, or workflow definition. Our long-term goal is to build a generic system, called a model management system, for manipulating models and mappings between models. Such a system would make it easier to build meta data driven applications, such as modeling tools, data translators, and mediators for Web sites. One key model management operator is Merge. Merge combines two models, returning all information expressed in either model. Merging two models is difficult because it is hard to determine how the two models are related, and because Merge must reconcile different structures that express the same concepts. We discuss a generic Merge operator in the context of a model management system.