Conceptual Modeling: Past, Present and the Continuum of the Future

In this paper we give a brief history on conceptual modeling in computer science and we discuss state-of-the-art approaches. It is claimed that a number of problems remain to be solved. "Schema-first" is no longer a viable approach to meet the data needs in the dynamic world of the internet and web services. This is also true for the "schema-later" approach simply because data and data sources constantly change in depth and breadth and can neither wait for the schema to be completed nor for the data to be collected. As a solution we advocate for a new "schema-during" approach, in which the process of Conceptual Modeling is in a continuum with the operations in the database.