本研究分析90到94年度國民中學學生基本學力測驗國文科和英語科成就性別差異和性別差別試題功能（differential item functioning，簡稱DIF）。在成就差異分析方面，本研究發現國文科和英語科的性別差異組型非常相似，具體言之，女生表現一致顧著高於男生，男生個別差異皆較女生略大些，兩科之低成就組以男生居多，高成就組以女生居多，不過高成就組男女生人數比例差距不及低成就組大。在性別DIF分析方面，國文科DIF出現率約為7.5%，有利男生者和女生者個半；英語科DIF出現率則不到1%，有利女生者佔0.7%，有利男生者佔0.2%。不同內容類型試是的DIF出現率不等，國文科以「組織結構」、「詞語」、「字音、字形、字義」和「段篇」題的出現率較高些；英語科DIF題都來自「生活情境閱讀」題。篇末根據研究發現提出建議供相關人員參考。

This research investigated the gender differences and gender differential item functioning (DIF) on the Chinese and English Basic Competency Tests for Junior High School Students (BCTEST) from 2001 to 2005. The results showed similar pictures of gender differences on the Chinese and English parts of the BCTEST. Specifically, the females consistently performed significantly better than the males, and the score variations of males were slightly larger than those of females across test administrations. In addition, the proportion of males was much higher than those of females in the low-achieving groups, and the proportion of females was slightly higher than those of males in the high-achieving groups. The results on DIF analyses showed that the average percentage of items displaying gender DIF were respectively about 7.5% and 0.9% on Chinese and English tests. The number of items presenting DIF on Chinese tests favoring males was equal to those favoring females. The items presenting DIF on English tests favoring males were about 0.2% and favoring females were about 0.7%. The proportions of DIF items across different item contents showed variations, the content areas that yielded more DIF items were those associated with structure and organization, paragraph reading, characters or vocabulary on Chinese tests, and real life context reading on English tests. Implications based on findings were proposed for educators, test developers and researchers.