1. A method, implemented by a computing device, comprising: receiving stroke information relating to a partially written East Asian character, the partially written East Asian character being composed of one or more radicals; identifying the one or more radicals contained in the partially written East Asian character via one or more trained hidden Markov models; selecting a radical in a prefix tree, wherein the prefix tree branches to East Asian characters as end states, the selecting comprising: calculating a best partial matching score between the one or more radicals contained in the partially written East Asian character and the radical in the prefix tree; and calculating a partial matching score for each character in the prefix tree based on the best partial matching score; identifying an East Asian character as an end state from the prefix tree based on the partial matching score; receiving user input to verify that the identified East Asian character is the end state for the partially written East Asian character; and replacing the received stroke information with the identified East Asian character verified by the user input.