Any theory of language acquisition must take into account the actual speech heard by children during the acquisition period. When 8 well-educated mothers were tape-recorded talking to their daughters, ages 16 to 30 months, it was found that their speech differed significantly from that spoken to another adult. The mothers used a more restricted…

Using string-manipulation algorithms, FORTRAN computer programs were designed for analysis of written material. The programs measure length of a text and its complexity in terms of the average length of words and sentences, map the occurrences of keywords or phrases, calculate word frequency distribution and certain indicators of style. Trials of…