This article constructs a static model of information acquisition when the agent does not know exactly what pieces of information he is missing. A representation of preferences over information channels and menus of lotteries is shown by adapting the model of unforeseen contingencies by Dekel et al. (Econometrica 69:891–934, 2001; Econometrica 75:591–600, 2007), which is an extension of Kreps (Econometrica 47:565–576, 1979; Economic analysis of markets and games: essays in honor of Frank Hahn, 1992). Also, characterisation of informativeness of an (...) information channel analogous to the one by Blackwell (Ann Math Stud 24:265–272, 1953) is examined in conjunction with the preference for flexibility by applying the structure of Shapley value. (shrink)