The number of developed countries that have initiated standardized education reform has increased over the last two decades. At the same time that the ministry of education in Taiwan implemented the 12-year basic education policy, they announced regulations for implementing a standardized comprehensive assessment program to monitor the achievement of junior high school students. This study investigated the implementation of a standardized classroom literacy assessment for English classes in junior high schools as an alternative formative-assessment option. In this study, we developed a standardized seventh-grade English (L2) reading-literacy sample task and collected student work and feedback from participating teachers and students. The reading task was scenario-based and required that students search for missing pets. The study results are as follows: (1) Nearly 70% of the participating students agreed that the high-quality scenario-based reading task was more interesting, fulfilling, and challenging than traditional tests. (2) The use of a standardized approach for assessing English reading literacy can enhance the learning motivation of students because it not only grants students the freedom to respond diversely (e.g. to demonstrate understanding by drawing pictures or using Chinese, their first language), but also helps students to learn English more effectively through post-assessment feedback. (3) The scenario-based reading task is an assessment that is useful for learning because it encourages students to apply knowledge to real-life problems, clarifying for students the meaning and value of learning English. Therefore, if a standardized literacy assessment is implemented in Taiwan’s junior high school English classrooms, then students can gain motivation not only for learning English but eventually for lifelong learning, which is the ultimate goal of Taiwan’s 12-year basic education curriculum reform.