Informal Description of Data Models

From Wikipedia, the free encyclopedia, a data model is a model that
describes in an abstract way how data is represented in a business
organization, an information system or a database management system.

Another way of saying this is that you want to be able to represent concepts
of information and their relationships. For example, within PSA/PDS, we
work with planetary missions and the associated science data sets produced
by spacecraft instruments. A PSA/PDS data model would include the formal
definition of missions, data sets, and instruments, and their relationships.

There are also different levels of models, from very abstract to very detailed.

A scoping model is a high level representation of a domain that represents
the major information topics about which data and metadata will be
collected. This model is used to communicate a domain view regarding the
boundaries of information modeling. The first attached JPG image illustrates
a draft scoping model for the PDS. It is in Unified Modeling Language
(UML) notation and simply shows the key concepts and their relationships.
The second JPG image illustrates the same information with the IPDA
prototype keywords added.

A conceptual model documents the domain data requirements by defining
the modeling primitives. The conceptual model is constructed to enable
reasoning within an idealized logical framework. The third attached image
illustrates a draft PDS conceptual model.