Since the size of problem space for syllable-to-word (STW) conversion is much less than that of syllable-tocharacter (STC) conversion, the most pinyinbased Chinese input systems (Hsu, 1994; Hsu et al., 1999; Tsai and Hsu, 2002; Gao et al., 2002; Microsoft Research Center in Beijing;<cite> Tsai, 2005)</cite> are addressed on STW conversion.