1. A method comprising, by one or more computing devices: receiving, from a first client system of a first user, a first query inputted by the first user at the first client system, the first query comprising one or more n-grams; identifying one or more ideograms, each ideogram being associated with one or more tags, each identified ideogram being associated with at least one tag matching at least one of the n-grams of the received first query; calculating, for each identified ideogram, a use-probability for the ideogram given the received first query, wherein the use-probability is based at least in part on a frequency of use associated with the ideogram; sending, to the first client system, instructions for presenting a first set of ideograms comprising one or more of the identified ideograms, the first set being determined based on the calculated use-probabilities associated with the ideograms; receiving a second query from a second client system of a second user, the second query inputted by the second user at the second client system, the second query comprising one or more n-grams; and identifying one or more ideograms, each identified ideogram associated with at least one tag matching at least one of the n-grams of the received second query.
1. A method comprising, by one or more computing devices: receiving, from a first client system of a first user, a first query inputted by the first user at the first client system, the first query comprising one or more n-grams; identifying one or more ideograms, each ideogram being associated with one or more tags, each identified ideogram being associated with at least one tag matching at least one of the n-grams of the received first query; calculating, for each identified ideogram, a use-probability for the ideogram given the received first query, wherein the use-probability is based at least in part on a frequency of use associated with the ideogram; sending, to the first client system, instructions for presenting a first set of ideograms comprising one or more of the identified ideograms, the first set being determined based on the calculated use-probabilities associated with the ideograms; receiving a second query from a second client system of a second user, the second query inputted by the second user at the second client system, the second query comprising one or more n-grams; and identifying one or more ideograms, each identified ideogram associated with at least one tag matching at least one of the n-grams of the received second query. 15. The method of claim 1 , further comprising: receiving a request from the first client system to access one or more restricted ideograms, wherein the first user is not authorized to access the restricted ideograms; and sending instructions for purchasing access to the one or more restricted ideograms to the first client system for display to the first user.