Table 1

Category	Description	Ontological Sensitivity	Fidelity Verification	Evaluation Type	Tool Availability
Ontology-Driven Frameworks	Semantic backbone for requirement generation	High	Formal reasoning, validation rules	Automated + human review	IJASEIT, OBFRE
Pattern-Based Templates	Controlled NL templates aligned with ontology elements	Medium	Rule-based checking	Human review	RE-Onto Gen
Model-to-Text Transformation	Direct UML/Onto UML → NL using mapping rules	High	Traceability checks	Automated	Onto Trace
Hybrid & LLM-Assisted Systems	LLM + reasoning engine for NL generation	Medium-High	Post-generation human validation	Automated + human review	Onto LLM

Table 1: Extended Taxonomy of Onto UML-Based NL Generation Approaches

Table 2

Onto UML Element	Example Sentence	Semantic Fidelity Notes
Kind	A Customer is a person who purchases products.	High; preserves ontological type
Role	A Seller is a person who sells products to customers.	High; role dependency maintained
Relator	A Purchase links a Customer with a Product.	Medium; relation captured
Phase	An Employee may be promoted to Manager phase.	High; temporal state preserved
Mixin	A Person can be both a Customer and an Employee.	High; multiple classification preserved

Table 2: Onto UML–NL Mapping Examples [28]

Tables at a glance

Table 1

Table 2