This paper aims to advance our understanding of how children's use of vocabulary in writing
changes as they progress through their school careers. It examines the extent to which a
model of lexical sophistication as use of low-frequency, register-appropriate words
adequately captures development in vocabulary use across the course ...
This paper aims to advance our understanding of how children's use of vocabulary in writing
changes as they progress through their school careers. It examines the extent to which a
model of lexical sophistication as use of low-frequency, register-appropriate words
adequately captures development in vocabulary use across the course of compulsory
education in England. We find that the received model needs elaborating in a number of
important ways. Specifically: 1) The average frequency of words in the repertoire used by
older children is no lower than that of younger children. However, younger children's writing
is characterized by extensive repetition of high frequency verbs and adjectives and of low
frequency nouns (the latter being a product of a focus on entities which are rarely discussed
in adult writing). The role of repetition in this finding implies that lexical sophistication is
inseparable from lexical diversity, a construct which is usually treated as distinct. 2) Younger
children's writing shows a preference for fiction-like vocabulary over academic-like
vocabulary. As they mature, children come to make greater use of academic vocabulary in
both their literary and non-literary writing, though this increase is greatest in their nonliterary writing. Use of fiction vocabulary remains constant across year groups but decreases
sharply in non- literary writing, showing an enhanced sense of register appropriateness. This
development of register appropriate word use can be captured by relatively simple frequencybased measures that could readily be employed by teachers and researchers to track writers'
development in this aspect of word use.