修改過程，其實也是一種建構和提煉語言的過程。Barr（1983）的研究表明，「修改」可以提高學生的寫作程度。本研究以3所一般程度（band 3）的中學的中三級學生為對象。每所中學各選一個實驗班，進行符號批改作文實驗。根據 t-test檢定，實驗班學生在兩次（第一次教師採用傳統精批細改法，第二次則採用符號批改法）修改作文副本中所得成績有顯著的差異。實驗證明，符號批改較傳統的精批細改的效果較為優勝。符號批改法可以培養學生思考和分析問題的能力，因為在作文中所作的每一處改正，學生都要開動腦筋。符號批改法可以培養學生在寫作方面的責任感，更可以幫助學生成為「有效的修改者」。

The revision process is in fact a process of structuring and shaping language (Fitzgerald, 1987; Somer, 1980; Stallard, 1974). Barr’s (1983) research has demonstrated that revision can enhance students’ writing ability. In the present study, “symbol marking” was tested on Form Three students from three local average-ability (Band 3) secondary schools. One Form Three classes in each school were invited to participate in the experiment. Students were asked to revise their own compositions two times. The first time, the compositions were marked first by the teacher using “tradition marking,” and students were asked to revise them according to the teacher’s markings two weeks later. The second time, the compositions were also marked first by the teacher, but using “symbol marking.” Students were also asked to revise their compositions two weeks later, according to the teacher’s markings. T-test results showed that “symbol marking” is a more effective way of marking students’ compositions. Students achieved significantly higher scores in the second revision where the teacher used “symbol marking” to mark the compositions. “Symbol marking” enhances students’ thinking and analytical ability because students were required to think and analyse each correction marked. “Symbol marking” can develop students’ sense of responsibility in their writing, and can facilitate students to become effective proof-readers.