According to (Becker, 1985; Huang, 1985; Gu et al., 1991; Chung, 1993; Kuo, 1995; Fu et al., 1996; Lee et al., 1997; Hsu et al., 1999; Chen et al., 2000; Tsai and Hsu, 2002; Gao et al., 2002; Lee, 2003;<cite> Tsai, 2005)</cite> , the approaches of Chinese input methods (i.e. Chinese input systems) can be classified into two types: (1) keyboard based approach: including phonetic and pinyin based (Chang et al., 1991; Hsu et al., 1993; Hsu, 1994; Hsu et al., 1999; Kuo, 1995; Lua and Gan, 1992) , arbitrary codes based (Fan et al., 1988) and structure scheme based (Huang, 1985) ; and (2) non-keyboard based approach: including optical character recognition (OCR) (Chung, 1993) , online handwriting and speech recognition (Fu et al., 1996; Chen et al., 2000) .