Lexical acquisition in naturalistic contexts
The thesis investigates ways in which young children acquire meanings of novel
words. Various accounts of word learning postulate that the nature of the word
exposure context plays a crucial role in supporting lexical acquisition (e.g. Clark.
1997; Nelson, 1988). Children are sensitive to a range of input, such as syntactic
cues (Gleitman, 1990), gestures (Kobayashi, 1997) and verbal explanations of
word meaning (Dickinson, 1984). The present research aimed to further our
understanding of types of word exposure that help children acquire novel words,
by examining the process of lexical acquisition in naturalistic contexts. The
research was carried out in an educational context; the emphasis was on
vocabulary acquisition in the classroom and children's acquisition of science
terms, commonly encountered at school. The range of knowledge children
acquired about word meanings was assessed using a variety of lexical tasks (e.g.
production and comprehension tasks).
The research was divided into three phases. Phase 1 focused on the measurement
of lexical knowledge. It considered the ways in which drawing-based tasks tap
lexical knowledge. Phase 2 evaluated the importance of the word exposure
context in lexical acquisition by investigating children's learning of words that
were classed as 'difficult' to learn. Finally, phase 3 explored different kinds of
word introduction that help children acquire word meanings. This phase of the
research was conducted in classroom settings.
Drawing assessments were found to make an important contribution to the
assessment of lexical knowledge. Findings from phases 2 and 3 showed that
ways in which novel words are introduced plays a crucial role in supporting
lexical acquisition, and also the range of vocabulary knowledge children acquire
(e.g. production and comprehension). Types of exposure that help children
acquire words in classroom contexts were identified. The results are discussed in
relation to implications for teaching practice and an account of lexical