Ambiguity, complete ignorance, Belief Update, D.D8.D81 - Criteria for Decision-Making under Risk and Uncertainty, belief update, Multiple Priors, Confidence, Update on Surprising or Null Events, Decision theory, Complete ignorance, D.D8.D83 - Search • Learning • Information and Knowledge • Communication • Belief • Unawareness, [SHS.PHIL] Humanities and Social Sciences/Philosophy, multiple priors, update on surprising or null events, ambiguity, confidence, [SHS.GESTION] Humanities and Social Sciences/Business administration, [SHS.ECO] Humanities and Social Sciences/Economics and Finance, Rationality and learning in game theory