Sherman also showed how individual writers are remarkably consistent in their average sentence lengths. This consistency was to become the basis for the validity of using samples of a text rather than the whole thing for readability prediction.

Sherman was the first to use statistical analysis for the task of analyzing readability, introducing a new and objective method of literary criticism. Another of Sherman's discoveries was that over time sentences not only became shorter but also simpler and less abstract. He believed this process was due to the influence of the spoken language on written English. He wrote (p. 312):

Literary English, in short, will follow the forms of the standard spoken English from which it comes. No man should talk worse than he writes, no man writes better than he should talk.... The oral sentence is clearest because it is the product of millions of daily efforts to be clear and strong. It represents the work of the race for thousands of years in perfecting an effective instrument of communication.

Linguistic research later confirmed Sherman's view of the relationship between spoken and written language. Rudolf Flesch (1946) wrote that English is following written Chinese in making language simpler by substituting standard word order (subject-verb-object) for more complex grammar.

Fig. 2. In Analytics of Literature, L.A. Sherman looked at literature statistically. He showed the importance of average sentence length and the relationship between spoken and written English.

According to Flesch, Chinese is "the most grown-up talk of mankind. It is the way people speak who started to simplify their language thousands of years ago and have kept at it ever since...."(p. 12). "Among the world's great languages, the runner-up to Chinese is English. It's simpler, more flexible, more practical than any other Western language because it has gone furthest in losing inflections and straightening out irregularities" (p. 20)

Sherman's most important point was the need to involve the reader. He wrote:

The universally best style is not a thing of form merely, but must regard the expectations of the reader as to the spirit and occasion of what is written. It is not addressed to the learned, but to all minds. Avoiding book-words, it will use only the standard terms and expressions of common life... It will not run in long and involved sentences that cannot readily be understood. Correct in all respects, it will not be stiff; familiar, but safely beyond all associations of vulgarity (p. 327).