This week Dr. Tim Scarfe, Dr. Keith Duggar and Yannic Kilcher discuss multi-arm bandits and pure exploration with Dr. Wouter M. Koolen, Senior Researcher, Machine Learning group, Centrum Wiskunde & Informatica.




Wouter specialises in machine learning theory, game theory, information theory, statistics and optimisation. Wouter is currently interested in pure exploration in multi-armed bandit models, game tree search, and accelerated learning in sequential decision problems. His research has been cited 1000 times, and he has been published in NeurIPS, the number 1 ML conference 14 times as well as lots of other exciting publications.




Today we are going to talk about two of the most studied settings in control, decision theory, and learning in unknown environment which are the multi-armed bandit (MAB) and reinforcement learning (RL) approaches


- when can an agent stop learning and start exploiting using the knowledge it obtained


- which strategy leads to minimal learning time




00:00:00 What are multi-arm bandits/show trailer


00:12:55 Show introduction


00:15:50 Bandits 


00:18:58 Taxonomy of decision framework approaches 


00:25:46 Exploration vs Exploitation 


00:31:43 the sharp divide between modes 


00:34:12 bandit measures of success 


00:36:44 connections to reinforcement learning 


00:44:00 when to apply pure exploration in games 


00:45:54 bandit lower bounds, a pure exploration renaissance 


00:50:21 pure exploration compiler dreams 


00:51:56 what would the PX-compiler DSL look like 


00:57:13 the long arms of the bandit 


01:00:21 causal models behind the curtain of arms 


01:02:43 adversarial bandits, arms trying to beat you 


01:05:12 bandits as an optimization problem 


01:11:39 asymptotic optimality vs practical performance 


01:15:38 pitfalls hiding under asymptotic cover 


01:18:50 adding features to bandits 


01:27:24 moderate confidence regimes  


01:30:33 algorithms choice is highly sensitive to bounds 


01:46:09 Post script: Keith interesting piece on n quantum 




http://wouterkoolen.info


https://www.cwi.nl/research-groups/ma...




#machinelearning