the children used a preemption “strategy” and preempted use of the novel word with the
known word. That would be an example of the principle of contrast (Clark, 1987).
In later work, however, Dockrell and Campbell (1986) compared the introduction of new
words and objects using perceptual and lexical contrasts (e.g., “Pass me the gombe block,
not the red or green one”). In this study, preemption did not preclude the children learning
a synonym for known terms. Thus, Dockrell and Campbell (1986) suggested that
preemption may be a significant variable only at particular stages and in particular
circumstances.
Banigan and Mervis (1988) investigated the relative effect of four input strategies in
inducing the 2-year-old children to learn the adult-appropriate label and begin to form a
new category. Seven object pairs were used (e.g. horn-funnel or horse-unicorn). The four
input strategies were presented in four conditions. In all conditions the input was
presented twice, during which the child was told the label for an object a total of four
times. The conditions differed in the information provided in addition to the object name.
In the label only condition, no additional information was provided. In the
IabelZdescription condition, the child was given a verbal description of the object which
included the critical form-function correlation that made the object a member of the
adult’s-basic category. In the IabelZdemonstration condition, the child was given a
demonstration of the same form-function correlation as was described in the
IabelZdescription condition. In the IabeizdemonstrationZdescription condition, the same
form-function correlation as in the two previous conditions was demonstrated while the
experimenter described it verbally. Comprehension and production tests were then
administered.
It was found that the most effective strategy involved labelling an object and providing
both a physical demonstration and a verbal description of important attributes that made
the object a member of the adult appropriate category. Neither the label plus verbal
description strategy nor the label only strategy was effective for children of this age.
More recently, Au (1990) investigated how children use the information given in a certain
context in order to acquire the meanings of new words. The first study investigated how
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