The different performance across measurements has also been highlighted by other studies.
Curtis (1987) demonstrated that different pictures of word knowledge emerge from different
criteria by testing fifth graders on a set of words using several different measures. She found
that they performed better on a checklist (students were to respond “yes” if they knew a
word) than when asked to explain the meaning of the words and were worse when they were
asked to give an example of the word. A very small number of students succeeded on the
synonyms and complete explanations tasks. Moreover, Heibeck and Markman (1987) found
that children’s performance on a word learning task varied as a way of measurement, with
the best performance shown on the comprehension task and the worst on the production task.
Children’s performance on each task demonstrated a different aspect of their understanding
of the target words. Success on the multiple choice task is probably the first element in the
lexical acquisition, and the one mostly tapped by the lexical acquisition studies. The child is
only required to recognize the item in a forced choice task. However, this does not show
anything about the overall understanding of the word’s meaning, and it would be very
superficial and dangerous to draw inferences about word learning based only on a multiple
choice task.
Concluding this subsection, it could be argued that the above findings demonstrate that
comprehension and production is not an all-or-nothing ability. There may be different levels
of comprehension and production. For example, if we take the case of comprehension,
success on the multiple choice task could be the first level of comprehension. Then success
on the rest of the understanding tasks could be mapped with more advanced levels. The
above suggestion is in accordance with Donaldson and Laing (1993) who have distinguished
three levels of comprehension (Level O: non-linguistic comprehension; Level 1: partial
linguistic comprehension; Level 2: full-linguistic comprehension).
Furthermore, the above suggestion is also in accordance with Oviatt (1980,1982) who
distinguished two distinct types of comprehension, the “recognitory comprehension” and the
“symbolic comprehension”. The “recognitory comprehension” which is referred to as an early
type of comprehension is defined as perceptual recognition of a linguistic form, association
of that form with some regularity in the environment, and awareness of the match between
the linguistic form and the intendent referent. The recognitory comprehension could be