1. A method comprising: receiving the identity of a first user; receiving a first dataset pertaining to the first user; receiving the identity of a first artifact; and applying a probabilistic familiarity algorithm to the first dataset with respect to the first artifact to yield a probabilistic familiarity value for the first artifact with respect to the first user; wherein: the first dataset is received over a computer network; and the first dataset includes at least one piece of personalized information for the first user.