The few existing studies all attempted to develop a unified statistical model to compute the probability of a word having a particular POS category for all Chinese unknown words (Chen et al., 1997; <cite>Wu and Jiang, 2000</cite>; Goh, 2003) . This approach tends to miss one or more pieces of information contributed by the type, length, internal structure, or context of individual unknown words, and fails to combine the strengths of different models.