Estimating naturalness in Japanese english textbooks

This paper describes work in progress to determine the degree to which English language textbooks used in Japan portray 'natural' English. We begin by elucidating this concept of 'naturalness' and proceed to compare three example textbook series drawn from different decades in Japanese ESL history. Our approach compares the extent to which the content of each textbook series reflects the characteristics of 'reference' language materials, on the grounds that these materials afford a plausible standard for natural English. The primary materials used for reference are the Brown corpus of American English and the British National Corpus of British English.