Definition

Citation volatility

Citation volatility is the degree to which repeating the same prompt on the same engine produces a different set of cited sources.

It varies sharply by engine: Perplexity's citation sets are comparatively stable, while ChatGPT's often share fewer than half their sources between two runs of the same prompt.

Volatility sets the floor on how small a change any amount of sampling can detect, and it is the reason single-reading screenshots are worthless as evidence.

Nostimates measures citation volatility across twelve AI answer surfaces. Request access →

All terms

AEO (Answer Engine Optimisation)GEO (Generative Engine Optimisation)AI Overviews AI Mode Citation share n-sampling Query fan-out Grounding Share of voice (AI)Extraction success rate Surface Answer engine Citation Brand mention Mention rate Confidence interval Statistical significance Non-determinism Reproducibility Identity-free collection Personalisation Locale Residential proxy Bot detection Collection cost Credit Evidence retention Audit trail Parser version Canary prompt Data freshness Cadence Prompt set Head term Long-tail query Competitive set llms.txt robots.txt AI crawler Training crawler Retrieval-augmented generation (RAG)Hallucination Answer box Featured snippet Zero-click search Entity Entity salience Knowledge graph Structured data JSON-LD schema.org FAQ schema Answer-first content Chunk Embedding Semantic search Prompt injection Market coverage Sentiment analysis Position tracking White-label data