Local Item Dependence on the Vocabulary Levels Test Revisited
Tadamitsu Kamimoto
Kumamoto Gakuen University
doi: http://dx.doi.org/10.7820/vli.v03.2.kamimoto
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Abstract
The purpose of this study was to address the question of local item
dependence (LID) on the Vocabulary Levels Test (VLT). The test format
adopts a matching format consisting of six words and three definitions.
A review of the literature suggested that items presented in such a format
cannot be considered independent. However, Schmitt, Schmitt, and
Clapham reported that according to Rasch analysis, most of the items
performed independently. The present study examined effects of LID
from a non-Rasch approach. A set of three clusters was collapsed into one
large cluster of 18 words and 9 definitions on the assumption that such a
treatment would make items practically independent. Both the collapsed
VLT and the intact VLT were given to 114 Japanese English as a Foreign
Language (EFL) students at an interval of one week. Results showed that
scores were 15% higher on the original VLT than on the collapsed form.
Furthermore, an LID index based on the correct/wrong response types
between the two tests indicated that scores on the original VLT were
about 19% inflated. Implications were drawn and discussed.

Citation
Kamimoto, T. (2014). Local item dependence on the vocabulary levels test revisited. Vocabulary Learning and Instruction, 3 (2), 56-68. doi: 10.7820/vli.v03.2.kamimoto