Synonyms Beat Hierarchy in Ontology Prompts

When prompting LLMs for ontology validation tasks, explicitly including entity synonyms improves performance more than adding extended hierarchical context.

The researchers tested prompt variations along three dimensions: natural language-friendly (NLF), extended context (EC), and synonyms (S). The best-performing prompts were NLF with synonyms, not NLF with extended parent-class hierarchies.

Possible explanation: LLMs already encode substantial synonym and lexical variation knowledge from pretraining. Making synonyms explicit in the prompt surfaces this existing knowledge. Hierarchical context, by contrast, requires the model to reason about relationships it may not have encoded.

Implication: When designing prompts for knowledge tasks, prioritize lexical breadth (alternative names, synonyms) over structural depth (hierarchies, relationships).

Related: 05-atom—nlf-prompts-outperform-structured, 06-molecule—prompt-design-dimensions-ontology