Another application of EAV is in modeling classes and attributes that, while not sparse, are dynamic, but where the number of data rows per class will be relatively modest – a couple of hundred rows at most, but typically a few dozen – and the system developer is also required to provide a Web-based end-user interface within a very short turnaround time. "Dynamic" means that new classes and attributes need to be continually defined and altered to represent an evolving data model. This scenario can occur in rapidly evolving scientific fields as well as in ontology development, especially during the prototyping and iterative refinement phases.