The use of computers makes possible analysis of the vast amount of data available in recent dialect dictionaries and surveys and in the ancient Chinese rhyme books, such as "Guang yun" and "Ji yun." Comparison of dialects can enable a historical study of Chinese, a major language group outside the Indo-European area, to offer "a more balanced perspective on the nature of sound change in human language." The problems of coding are great, but once the coding system is established, the encoding of materials can be shared by a number of institutions. The coding of the seven Mandarin dialects in the "Hanjy fangyin zihui" is complete, and preliminary tests of the computer program have shown it to be satisfactory. After further testing and refinement, other dialect surveys, rhyme books, and Sino-Korean, Sino-Japanese, and Sino-Annamese can be added to the system. The author gives details of the organization of the data, the coding system, the computer program, and errors in the source data. Appendices give the actual computer code, flow charts for the computer program, and a list of errors in the "Hanjy fangyin Zihui." Correspondence concerning POLA matters should be addressed to William S-Y. Wang, Department of Linguistics, University of California, Berkeley, California 94720. (MK)