Author name: Sébastien FAVRE

Sébastien Favre-Lecca is an artist-researcher and founder of NeoMundi. He is developing a real-time measurement layer for AI system behavior, designed to make variation, stability and selected risk signals observable, auditable and actionable. His work focuses on behavioral AI metrology, runtime observability, drift, factual validity, and the articulation between measurement, governance and independent infrastructures.

AI Weather, methodology
AI Observatory

How can we measure a change in AI behavior? The method behind AI Weather

If an AI system changes its behavior without changing its name, how would we notice? A single response is not enough. The same system can produce different answers to an identical question. Its behavior can also evolve over time, particularly when its model, settings, or infrastructure change. AI Weather™ makes some of these variations visible. […]

AI Barometer #13 – Orange level – Insufficient coverage, 10 of 12 systems measured – NeoMundi AI Observatory
AI Observatory

AI Barometer 13, September 7 to 13, 2026

All AI Barometers Observation level: 🟠 Orange — insufficient coverage Of 4,800 executions launched across 12 systems, 3,981 were fully measured, representing 82.94% coverage, below the 90% standard publication threshold. Mean stability stands at 0.922, with an overall semantic variation rate of 1.61%. Two systems produced no usable observations despite multiple attempts, accounting for 800

Students at Champlain College Saint-Lambert discovering NeoMundi’s AI Weather during an awareness session.
AI Observatory

NeoMundi Invited to Present AI Weather to Students at Champlain College Saint-Lambert

The NeoMundi team is pleased to take part in an educational initiative designed to help students better understand AI Weather and the reliability issues associated with generative artificial intelligence systems. Follow the #AIweather on X This initiative is exclusively educational. Its purpose is to help students become better-informed users of artificial intelligence: to understand that

AI Barometer #12 – Yellow level – Coverage down, global stability maintained – NeoMundi AI Observatory
AI Observatory

AI Barometer 12, August 31 to September 6, 2026

All AI Barometers Observation level: 🟡 Yellow Across 4,800 executions distributed among 12 systems, AI Barometer #12 remains overwhelmingly within the normal regime. Average stability remains virtually unchanged at approximately 0.923. The overall semantic variation rate stands at 1.41%, compared with 1.93% in Barometer #11. Coverage, however, decreased from 99.52% to 95.90%, with 197 incomplete

AI Barometer #11 – Green level held, global stability – Localized semantic variation – NeoMundi AI Observatory
AI Observatory

11th AI Barometer – August 24 to 30, 2026

All AI Barometers Observation Level: 🟢 Green Across 4,800 executions distributed among 12 systems, AI Barometer #11 remains largely in the normal regime, with average stability virtually unchanged around 0.923. Global semantic variation reaches 1.93%, compared with 1.57% in Barometer #10. Factual alerts remain limited, and no generalized shift of the panel is observed. Reading:

AI Barometer #10 – Green level held, global stability – Fluent factual error undetected – NeoMundi AI Observatory
AI Observatory

10th AI Barometer – August 16 to 23, 2026

All AI Barometers Observation Level: 🟢 Green Across 4,800 executions distributed among 12 systems, AI Barometer #10 remains largely in the normal regime, with average stability virtually unchanged at 0.9229. Global semantic variation decreases to 1.57%, compared with 2.09% in Barometer #9, while factual alerts remain limited. The observed movement remains mainly localized on a

NeoMundi AI Cartography August 2026: 12 AI profiles plotted by OpenAI factuality (horizontal axis) and Mistral factuality (vertical axis), point size indicating mean observed stability
AI Observatory

AI Cartography of August 2026: Measuring the Behavior of 12 LLMs

Two systems with almost the same stability can differ by more than 30 points in factuality Protocol 1 – 12 systems × 790 TruthfulQA questions NeoMundi’s August monthly cartography once again compares twelve de-identified AI profiles across several complementary dimensions: their behavioral stability over 790 TruthfulQA questions, the factuality of their responses independently assessed by

AI Barometer #9 – Global stability, localized variation – Factual hallucination in a fluent response – Green level – NeoMundi AI Observatory
AI Observatory

9th AI Barometer – August 9 to 16, 2026

All AI Barometers Observation Level: 🟢 Green Across 4,800 executions distributed among 12 systems, Barometer #9 remains largely in the normal regime (97.12%), with average stability virtually unchanged at 0.9228. Semantic variation, however, rises to 2.06%, compared with approximately 1.06% in the 8th Barometer, while factual alerts remain limited. The observed movement is mainly localized

AI Barometer #8 – First time at green level, global calm confirmed – Collective stabilization of profiles – NeoMundi AI Observatory – Green level
AI Observatory

8th AI Barometer, week of August 3–9, 2026

All AI Barometers Observation Level: 🟢 Green This week, AI Barometer #8 confirms a return to global calm and moves to the green level. Two movements are particularly notable: This edition also presents a new example of a fragile factual claim embedded in a fluent and convincing response. This case illustrates the potential value of

AI Barometer #7 – Global calm confirmed, punctual signal at 9% – Week of July 27 to August 2, 2026 – NeoMundi AI Observatory – Yellow level
AI Observatory

7th AI Barometer, Week of July 27 to August 2, 2026

All AI Barometers Observation Level: 🟡 Yellow This week, AI Barometer #7 highlights two complementary dimensions. On the one hand, the overall calm observed in AI Barometer #6 is confirmed: average semantic variation decreases, and the majority of profiles remain close to their usual regime. On the other hand, this return to calm is not

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