Taxonomy
The entities, classes and attributes in the Data Model are organized into a taxonomy.
As illustrated below, entities (marked with E) are organized into classes and subclasses
(marked with C). Each entity has its own set of attributes (marked with A). Entities
are grouped together based upon common characteristics.
Taxonomies arrange items into categories based on like characteristics. For example,
lesson plan and unit plan are both types of academic plans in the Data Model, but
lesson plan and unit plan differ based upon the scope and purpose of the plan. The
“is a type of” organization scheme ensures, with few exceptions, that each entity
has one, and only one, place in the arrangement. For example, in the Data Model,
a portfolio is a type of formative assessment is a type of assessment
is a type of instruction artifact.
Just like in the Linnaean taxonomy of living things,
a homo sapien is a type of hominidae is a type of primate is a
type of mammal is a type of chordate is a type of animal.
There are exceptions and hard-to-classify cases, similar to the duck-billed platypus
in the taxonomy of living things, which, as a mammal that lays eggs, defies a clean
classification.
The Data Model taxonomy is similar in form and function to other well-known taxonomies,
such as the Linnaean taxonomy of living things discussed above or historically used
classification systems such as the Dewey Decimal system. As one becomes familiar
with the structure of the taxonomy, locating a particular entity becomes easy. In
addition, the provided tools for using the Data Model have search features that
provide convenient means for locating items in the taxonomy.