A method and device for semantically reconciling complex data models is disclosed. A first transform is initially applied to received divergent complex data models in order to extract fundamental data representing selected divergent aspects of the complex data models that are to be reconciled. The extracted fundamental data are then semantically displayed in a manner suitable for both identifying differences between the aspects to be reconciled and for reconciling them. Input representative of a reconciliation of the fundamental data by a reconciling individual is received, and the fundamental data are reconciled accordingly to generate a single reconciled fundamental data set. The reconciled fundamental data set is then expanded into a corresponding reconciled complex data model by application of a second transform. The transforms are optionally capable of providing automatic enforcement of complex data model data abstractions and value dependencies during reconciliation.