Prompt Space Occupancy and Conversational Survival: The AIVO Meridian Measurement Architecture

This paper defines the measurement architecture of AIVO Meridian, a platform-specific AI brand measurement system operating across ChatGPT, Gemini, and Perplexity. Meridian is built on two complementary instruments: the Prompt Space Occupancy Score (PSOS) and the Conversational Survival Rate (CSR). PSOS measures the stability and quality of a brand's occupancy across the response space generated by AI models in purchase-intent query contexts. It operates across five dimensions: breadth, depth, resilience, sentiment, and decay. CSR measures whether a brand survives across consecutive turns within a single multi-turn AI conversation. Meridian runs four conversation types: 4-turn generic, 4-turn agentic, unlimited-turn generic, and unlimited-turn agentic. Agentic conversations name the brand as a starting anchor; the AI model then determines independently whether the brand survives to the final recommendation. We report a directional finding from live Meridian measurement: a decline in PSOS resilience for a prestige beauty brand preceded a 10-point CSR drop by one week. This observation supports the proposition that PSOS resilience functions as a leading indicator for CSR degradation. Meridian's architecture is independent of decision-stage filter methodology and constitutes a distinct measurement category from AI visibility indexing. Where visibility indexing captures presence at a point in time, PSOS measures the structural stability of that presence and CSR measures whether it survives the sequential reasoning process through which AI models generate final recommendations