With the advent of Model-Driven Engineering (MDE) several model transformation approaches and languages have been developed in the previous 5 years. Most of these existing approaches are metamodel-based with metamodels representing both an abstract syntax of the corresponding modeling language and also a data structure for storing models. However, this implementation specific focus makes it difficult for modelers to develop model transformations, because metamodels do not necessarily define all language concepts explicitly which are available for notation purposes. Therefore, we propose a by-example approach for defining inter-model mappings representing semantic correspondences between concrete domain models, which is more user-friendly, then directly specifying model transformation rules or mappings based on the abstract syntax. The intermodel mappings between domain models can be used to generate model transformation rules, by-example, taking into account the already defined mapping between abstract and concrete syntax elements. With this approach the user's knowledge about the notation of the modeling language is sufficient for the definition of model transformations regarding semantic correspondences. Hence, no detailed knowledge about the metamodel and the model transformation language is required.