抄録
Saida (2002) validated four Ibaraki Prefectural English Tests for high school students (IPET) administered in 1999 and 2000 using classical item analysis and factor analysis. This study explores the factor structures of the tests in detail. Sixteen English tests administered from 1995 to 2002 for first-year and second and third-year high school students were factor-analyzed and the dimensionality (the number of factors) of the tests was examined. The results showed the tests measured a single dominant ability. As a result of examining the factor structures in detail, however, items which were related to knowledge of English, such as grammar, vocabulary and so on, were clustered as a first factor and items which were related to an ability to infer from context were clustered as a second factor. Ways to improve the quality of the tests and the possibility of the application of item response theory to the tests are discussed.
