The importance of vocabulary is stressed in the upper elementary years when children
transition from 'learning to read' to 'reading to learn'. It is important to measure the breadth
and depth of vocabulary knowledge in order to understand learners' vocabulary knowledge;
thus, a two-battery, vocabulary test (i.e., antonym and synonym) was developed to measure the
learners' depth of vocabulary knowledge.
The purpose of this study was two-fold: (1) to compare the developmental patterns of
elementary students in vocabulary accuracy, and (2) to examine the types of errors and their
frequencies. A total of 402 elementary students participated in a two-battery, vocabulary test
(i.e., antonym and synonym). The major results can be summed up as follows. First, the
vocabulary accuracy results showed significant differences in both antonym and synonym tests
by grade level. Second, with respect to the rates of vocabulary errors, non-response errors were
highest, followed by semantic errors, morphological errors, and spelling errors. A summary of
the results, the limitations of this study, and directions for future studies are discussed.