Now that the latest technology can process huge amounts of data that was previously unimaginable, scientists can challenge established beliefs and prac-tices in many information-related fields. Xiaoet al. (2017) made such a challenge, focusing on the effec-tiveness of English textbooks popularly used in Chi-nese primary schools. They first assumed that pupils word recognition rate would equal the coverage rate of their textbook vocabulary lists. Then they used four reference corpora to calculate the latter, one of which was self-developed with an automatic web crawler. Finally, they concluded that textbook vocabulary lists were limited in timeliness, that the word recognition increment of the 6th graders was relatively small, and that word selection in textbook compilation should be adjusted. We would like to comment on their study from a Zipfian perspective as applied linguists in language acquisition.