In this episode of the Mr Barton Maths podcast, Craig sits down with Bibi Groot, behavioural scientist at Eedi, to unpack the rigorous research behind their ed-tech work. Bibi traces her journey from the UK's Behavioural Insights Team — where she applied frameworks like EAST (Easy, Attractive, Social, Timely) to public policy — to becoming Eedi's first behavioural scientist after a stint completing a PhD at UCL and having twins. The conversation builds methodically from the fundamentals of randomised control trials (and why they're so notoriously difficult to run well in schools) through the headline results of Eedi's two-year, 20-school RCT showing that students using the platform gained the equivalent of two to four extra months of progress, before diving into the much-publicised Google DeepMind collaboration. That study, run with LearnLM and a human-in-the-loop safety net, found that an AI tutor matched a human tutor on immediate question success and actually outperformed humans on short-term transfer questions — likely because the AI was relentlessly Socratic where time-pressured human tutors tended to short-circuit students' metacognition. Bibi closes by previewing Eedi's much larger four-arm follow-up trial (running until July 2026) testing whether deep student context beats strong pedagogy alone, plus exciting new pilots bringing DQR and WhatsApp-delivered AI tutoring to learners in Guyana, India, and Sub-Saharan Africa. Visit the show notes here: podcast.mrbartonmaths.com/221-building-an-ai-tutor-with-google-deepmind-with-bibi-groot-eedis-chief-impact-officer