Metamodel Usage Analysis for Identifying Metamodel Improvements

Modeling languages raise the abstraction level at which software is built by providing a set of constructs tailored to the needs of their users. Metamodels define their constructs and thereby reflect the expectations of the language developers about the use of the language. In practice, language users often do not use the constructs provided by a metamodel as expected by language developers. In this paper, we advocate that insights about how constructs are used can offer language developers useful information for improving the metamodel. We define a set of usage and improvement patterns to characterize the use of the metamodel by the built models. We present our experience with the analysis of the usage of seven metamodels (EMF, GMF, UNICASE) and a large corpus of models. Our empirical investigation shows that we identify mismatches between the expected and actual use of a language that are useful for metamodel improvements.