In conceptual modeling, what is “specialization”? Choose the description that best matches the process.

Introduction / Context:
Specialization and generalization are dual processes that organize data models according to shared and distinct characteristics. The question asks for the definition of specialization.

Given Data / Assumptions:

• We have a supertype that captures common attributes.
• We need to represent meaningful subsets with extras or constraints.
• The model links these via explicit supertype/subtype relationships.

Concept / Approach:
Specialization is the top-down process of creating subtypes from a supertype and establishing the supertype/subtype relationship to formalize inheritance and constraints. It is not about adding supertypes or ignoring the relationship.

Step-by-Step Solution:

Verification / Alternative check:
Modeling literature contrasts specialization (define subtypes) with generalization (derive a common supertype from several existing entity types).

Why Other Options Are Wrong:

• Creating supertypes from subtypes is generalization, not specialization.
• Defining subtypes but not forming relationships would not establish inheritance or constraints and is not correct terminology.

Common Pitfalls:
Confusing specialization with simple grouping; without a formed supertype/subtype link, the design loses integrity rules.

Final Answer:
Defining one or more subtypes of the supertype and forming supertype/subtype relationships.