In database modelling, generalisation ______ the differences among related…

Concept

Generalisation is a bottom-up abstraction process in an enhanced entity–relationship model. It combines related lower-level entity types into a higher-level supertype by identifying their common attributes and relationships.

Because the supertype retains what the entity types share, subtype-specific distinctions are suppressed at the higher level; in this sense, their differences are minimized.

Application

The blank asks what generalisation does to differences among related entity types. Generalisation focuses on common features and moves them into a shared supertype, so the required word is “minimizes”.

Contrast

• “maximizes” emphasizes distinguishing characteristics, which corresponds to moving toward specialization rather than forming a common supertype.

• “both maximizes and minimizes” combines opposite directions and therefore does not describe one generalisation operation.

• “neither maximizes nor minimizes” ignores the abstraction effect produced when common features are extracted.

Cross-check

For example, Car and Truck may be generalized as Vehicle by moving shared attributes such as registration number into Vehicle, while their distinct attributes remain in the subclasses. The higher-level representation therefore reduces the emphasized differences.

Result: generalisation minimizes the differences among related entity types.