Examining Passage-Related Local Item Dependence (LID) Using Q3 Indices in an EFL Reading Comprehension Test.

This paper reports the results of an analysis of a reading comprehension test using the Q subscript 3 (Q3) statistics developed by W. Yen (1984). Yen's Q3 can be a useful tool for examining local item dependence in the context of a reading comprehension test in which a set of related items is followed by a reading passage. Q3 is basically a pairwise index of local dependence, an interitem correlation of residuals that are obtained by subtracting theta-predicted scores from raw scores. This study reports the results of a Q3 analysis of a 40-item reading comprehension test taken by 1,857 English-as-a-Foreign Language high school students in Korea. Average interitem correlations of raw score and residuals within "passages" and "item types" were computed and compared to the grand mean of Q3 among all item pairs. Factor analysis were also conducted both on matrices of interitem correlations of raw scores and residuals. A considerable amount of local dependence was found to exist among items within passages, but no sizeable evidence of local dependence was found among items within item types. Factor analysis also confirmed this finding by successfully identifying passage-related factors in residuals. These results provide support for grouping items based on the passages for testlet analysis. (Contains 9 tables, 5 figures, and 64 references.) (Author/SLD)