related with performance in the analogy, definition, sentence generation, and multiple choice
task. The relation of the existing vocabulary knowledge with word learning has also been
demonstrated by other studies. For example, Gathercole et al., (1997) found that children’s
existing vocabulary knowledge (BPVS score) played a significant role in the long-term
learning of the sounds of new words.
Moreover, Robbins and Ehri (1994) found that children with larger vocabularies (PPVT-R
score) Ieamt more new words than those with smaller vocabularies as measured by a multiple
choice test. That finding contradicts with the findings of Experiment 1 which showed no
relation between children’s existing vocabulary knowledge and their performance on the
multiple choice task. A range of possible explanations for that discrepancy can be proposed.
It may be due to the different test of existing vocabulary knowledge used. Robbins and Ehri
used the PPVT-R vocabulary test, while the BPVS test was used in Experiment 1.
Vocabulary seems to be a fragile factor depending on how the lexicon is studied.
Nevertheless, since no significant relations were found in Experiment 1, Experiment 2 aimed
to constrain the factor “vocabulary knowledge” by measuring children’s prior lexical
knowledge of other items from the same semantic domain as the novel words. Thus,
Experiment 2 demonstrated that the children with high prior lexical knowledge (receptive and
expressive vocabulary) performed better across tasks than children with low prior lexical
knowledge. However, although significant correlations were found between children’s
expressive prior lexical knowledge and performance across tasks, the correlations between
children’s receptive prior lexical knowledge and performance across tasks tended towards
significance.
The above finding implies that children’s expressive prior lexical knowledge is more crucial
for acquiring the full meaning of a word than the receptive prior knowledge. Possibly,
expressive prior lexical knowledge reflects more advance levels of word knowledge (see
triangles at section 7.4.3.6) which can foster word learning than the receptive one.
Furthermore, the children’s prior lexical knowledge (expressive and receptive) for animals
was related to the acquisition of the target words describing animals across tasks and testing.
On the other hand, children’s prior lexical knowledge (expressive and receptive) for artifacts