To discover in explicit, definable terms just what characteristics distinguish the writing of older writers from that of younger ones would give teachers a better chance of teaching young children more successfully--of helping them mature. A passage was presented to hundreds of students in grades 4, 6, 8, 10, and 12. Fifty papers were chosen from each grade; these papers were equally representative of students with low, middle, and high scores on standardized achievement or ability tests. Students were told to study the passage and re-write it in a better way without omitting any information. What every student did to every one of the sentences he was told to re-write was tabulated. The results of this effort are discussed in detail. The writing skills of adults were also examined; conclusions concerning their level of language maturity are discussed. (CK)