Different approaches to information system (IS) development are based on different data models. The selection of a data model for conceptual design, among other things, depends on the problem domain, the knowledge, and the personal preferences of an IS designer. In some situations, a simultaneous usage of different approaches to the conceptual database design and IS development may lead to the most appropriate solutions. In our previous research we have developed a tool that provides an evolutive and incremental approach to IS development, which is based on the form type data model. The approaches based on the Extended Entity-Relationship (EER) and class data models are broadly accepted throughout the community of IS designers. In order to support the simultaneous usage of approaches based on the form type, EER and class data models, we have developed the Multi-Paradigm Information System Modeling Tool (MIST). In this paper, we present a part of our MIST tool that supports EER approach to a database design. MIST components currently provide a formal specification of an EER database schema specification and its transformation into the relational data model, or the class model. Also, MIST allows generation of Structured Query Language code for a database creation and procedural code for implementing database constraints. In addition, Java code that stores and processes data from the database, may be generated from the class model. In this paper, we present the evaluation study of the MIST EER domain-specific language. Users' perceptions of language quality characteristics are used for the evaluation. 
Concepts and evaluation of the extended entity-relationship approach to database design in a multi-paradigm information system modeling tool