Recent experiments have shown that people can learn in a few hours to dictate "1-page" letters in about the same time and with about the same quality as they write them. To determine how dictation performance improves with years of practice, 8 male business executives, highly experienced at dictation, were given the same tasks as were novices. Results show that the executives were 20-65% faster at dictating than at writing, not the 500% possible on the basis of maximum output rates of the 2 modalities. Compared with novice dictators, they dictated routine business letters about 20% faster, dictated more complex letters at the same rate, and wrote both types of letters a little slower. There were few qualitative differences between the performances of experienced and novice dictators. Output modality is not the limiting factor in composition. Rather, composition seems to be the fundamental skill, and method of composition is of secondary importance. (31 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1978 American Psychological Association.