Data modeling techniques are used in several ways -- domain data modeling (analysis), logical data modeling (detailed analysis), architectural data modeling, and physical data modeling (design). It is perfectly fine to use data models for several purposes, or different types of models for a similar purpose. For example, you can use data models, CRC models, UML class diagrams, and ORM diagrams for domain modeling; as Agile Modeling (AM) suggests, know Multiple Models so that you can and Apply the Right Artifact(s) for the situation. In this article I discuss a agile/evolutionary approach to data modeling.