2011 Volume 7 Issue 1 Pages 121-132
Prefecture-wide English achievement tests for high school students have been conducted twice a year in Kanagawa. The English committee of Kanagawa prefecture has created the English test at four difficulty levels. 43,546 students in 73 senior high schools took the 2009 spring tests on the same day. To counter the current decline in the number of test takers, the English committee decided to modernize the testing system in order to compare test scores among forms and to show the progress of students’ English ability on a common scale. The committee developed the four forms of the 2009 spring tests with a common item design. We equated them using item response theory. As a result, the test scores and the item parameters became comparable among forms. By including some items of the 2008 fall test in the 2009 spring test, the scores of students who took the both tests became comparable. This research demonstrates the importance of creating a common scale for large-scale achievement tests. Ways to improve such a teacher-based assessment system are also discussed.
