Preface to CoMoL 2009

Conceptual modelling has changed over years. Database applications form an integral part of most computational infrastructures. Applications are developed, changed and integrated by specialists in conceptual modelling, by computer engineers, or by people who do not have sufficient related background knowledge. Conceptual databases models are everywhere in applications and are likely to interfere with other models such as functionality models, distribution and collaboration models, and user-interface models. Models also depend on the cultural and educational background of their developers and users. Models typically follow applications, infrastructures, currently existing systems, theoretical and technological insight, and reference models provided by successful applications or literature. This basis of conceptual models is constantly changing and therefore models are constantly evolving or quickly become outdated. Applications are starting in a separated form and are later integrated into new applications. The coherence and consistency of the many coexisting models at best is partially addressed. Furthermore, models not necessarily share their targeted level of abstraction. Recently modelling is challenged by liberation of data from structure and the integration of derived or aggregated data, e.g. in streaming databases, data warehouses and scientific applications. Typically models for applications start at an intermediate level and size. Later they evolve, grow, and tend to become incomprehensible. Nowadays conceptual modelling in the small has become state of the art for specialists and educated application engineers. Conceptual modelling in the large has been mainly developed within companies that handle large and complex applications. It covers a large variety of aspects such as models of structures, of business processes, of interaction among applications and with users, of components of systems, and of abstractions or of derived models such as data warehouses and OLAP applications. Conceptual modelling in the large is typically performed by many modelers and teams. It also includes architectural aspects within applications. At the same time quality, configuration and versioning of models developed so far become an issue. We selected for the workshop three papers from nine submitted. We are sure that these papers reflect in a very good form the current state of the art. We thank the program committee members and additional reviewers for their support in evaluating the papers submitted to CoMoL'09. We are very thankful to the ER'09 organisation team for taking care of workshop proceedings.