Method for cold start of a multi-armed bandit in a recommender system

Smriti Bhagat and Stéphane Caron. US Patent Application US-20150012345-A1.


I'm not particularly proud of this. The patent system stems from a laudable principle: incenting companies to disclose technological knowledge, lest it is lost if the company shuts down. Yet, contemporary patent systems suffer from patent trolls. Legal threats, and the resulting dynamics where companies file offensive or defensive patents, makes me doubt that patents support technological advancement so much as they participate in monopoly consolidation.


A method performed by a recommender system to recommend items to a new user includes calculating reward estimates from multiple multi-armed bandit models of a user and her social network friends. The new user's social network friends have multi-armed bandit models that are well established. The mixed multi-armed bandit estimates are processed to select the arm that maximizes the estimated reward to the new user. The multi-armed bandit arm of the greatest reward estimate is played and the new user responds by providing feedback so that the new user's multi-armed bandit model is updated as time progresses.


  title = {Method for cold start of a multi-armed bandit in a recommender system},
  author = {Smriti Bhagat and St{\'e}phane Caron},
  year = {2015},
  month = jan,
  note = {US Patent App. 14/308,044},
  url = {},
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