In a data model: nouns and predicates

John O'Gorman asks (LinkedIn Data Modeling 2020 April)

Why do data models only include nouns? Second, the word 'Status' is a noun, right? If I use it as the name of a set, could I include the words 'Active', 'Inactive', 'Stalled', and 'Inverted' as members of the set? If so, could I include them in a data model as Concepts even though they are clearly not nouns?

Ken Evans answers:

Not true. A proper data model has nouns and predicates that define the relationships between the nouns.

Everest responds:
First, for data modeling, I note that a noun implies a population of "things". Perhaps the hardest but most important part of building a data model is in defining the members of that population so we can always determine what is included and what is excluded from the population.
Not only nouns and predicates (verb phrases) but also adjectives, understanding that an adjective serves to restrict the population of the noun. A noun qualified by an adjective would name a subset of the noun population, e.g., Employee, and full-time Employee.

Definitions of concepts should start with their supertype. Why not?

Andries van Renssen -posts on LinkedIn. 

A good definition of a concept should build on the definition of more generalized concepts. This can be done by two parts of a definition:

1. Specifying that the concept is a subtype of some other more generalized concept.

2. Specifying in what respect the concept deviates from other subtypes of the same supertype concept.

Such kind of definitions have great advantages, such as:

‑ The definition of (and the knowledge about) the supertype concept does not need to be repeated, as it is also applicable ("by inheritance") for the defined (subtype) concept.

‑ The definition implies a taxonomy structure that helps to find related concepts that are also subtypes of the same supertype (the 'sister‑concepts'). Comparison with the 'sister‑concepts' greatly helps to refine the definitions. Furthermore, the definitions prepare for creating an explicit taxonomy.

‑ Finding the criteria that distinguishes the concept from its 'sister concepts' prepares for explicit modeling of the definitions, which prepares for computerized interpretation and the growth towards a common Formal Language.

--Thus, why not?