written environments, from signs and letters to magazines and books. Intentional sources
for learning vocabulary are ones in which the explicit purpose of an interaction is to Ieam
the meaning of a word. These include a learner’s decision to consult a source, such as a
dictionary or a more knowledgable person, and direct instruction on the meanings of the
specific words.
Most of the fast mapping studies - focusing on the role of input for word learning - can be
categorised into two groups: those in which the context of presentation of the new word
was an artificial one and those that used a more natural context of presentation like a story
reading. Examples of both types of studies are presented in the next subsections.
3.2.1 Evidence from Traditional Fast Mapping Studies
The study cited most frequently as representing the fast mapping paradigm is that of
Carey and Bartlett (1978), in which the new word “chromium” was introduced to 3- and
4- year - old preschool children in a naturalistic setting. The teacher, when setting up for
a snack, individually asked each child: “See those two trays? Bring me the chromium one,
not the red one, the chromium one”. The use of an explicit contrast, “red” versus
“chromium” indicated “chromium” as a colour word and was intended to allow the child
to identify readily the referent (the olive-coloured tray).
With comprehension and production tasks administered one week later, Carey and
Bartlett (1978) found that one to two encounters with the word had allowed at least half
of the children to map something about the word in long-term memory. As noted by
Carey and Bartlett (1978) the children’s partial mappings of “chromium” were quite
variable and highly dependent on the child’s preexisting colour lexicon and the name the
child used for “olive” during pretests.
Other studies have examined word learning of known concepts in young children with
particular interest in which words would be learned faster, words for objects with existing
labels or words for objects with unknown labels. One such study is that of Dockrell
(1981) in which children had to identify the referent in a picture when an unknown word
was used. When children had already a name for an object, they had more difficulty
indicating that object as the new word. As suggested by Dockrell and Campbell (1981),
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