Mean Sentence Length Compared With Long and Short Sentences as a Reliable Measure of Language Development

Although the mean length of sentence is a very valuable index of language development, it does not give due weight to sentences which lie at the extremes of the distribution. In analyzing 21,800 remarks of 436 children2 the writer found that nearly 20 per cent were of only one word, while on the other hand there were many sentences which reached 20, 30, and even 50 words. These very long and very short remarks are here compared with mean sentence length from the standpoint of reliability and the portrayal of group differences in development.