作者：单俊林 王丹
　　【Abstract】In nature， writing is a linguistic， social-cultural and cognitive activity. Through assessment， students’ practical language competence could be reflected， what can also be reflected are the teacher’s success or teaching deficiency. This study takes assignments from two undergraduate classes， the contents and scores of the students’ writings are analyzed by reliability and validity， with the aim of obtaining a feedback which would be helpful to future teaching and learning.
　　【Key words】reliability； validity； writing
　　1. Introduction
　　Effective language test measures how many teaching goals have been achieved， how much knowledge students have learned in order to get positive washback effects of the instruction implemented. Writing is regarded as important aspect of language output. Writing test is valued as one of the most scientific and effective ways to evaluate learners’ language proficiency， and thus becomes an important and necessary component of many large-scale English tests.
　　2. Students’ writing test
　　Diverse types of language test exist and they differ from one another due to the test method and purpose. They can be classified into different perspectives， but the following four types are most common：proficiency test， diagnostic test， placement test and achievement test.
　　This paper is based on achievement tests taken by two English Major classes. In the test，， students are asked to write compositions based on short stories from the textbook， and the composition should contain two parts：a short review and a literature criticism. The length of the composition is not strictly limited and the number of students is around 40.
　　2.1 Achievement test
　　Achievement test is generally divided into two types：final achievement test and progress achievement test. As the terms indicate， “final achievement test is conducted at the end of a study course”；while progress achievement test “measure the progress that students are making”. Undoubtedly， the content of these tests must be relevant to the given courses.
　　Different from proficiency tests， achievement tests have something to do with language courses， and the purpose of them are to assess “how successful an individual student， groups of students， or the courses themselves have been in achieving the objectives”.
　　2.2 Writing test
　　Writing test is used when the teacher wants to know whether the students have mastered what has been taught in class according to certain teaching objectives. An achievement test is related directly to the lessons， or even a curriculum. Therefore， a writing test should be narrowly focused on particular teaching and learning goals and curriculum， and hence it is an achievement test.