當討論如何寫一篇論證文章（argumentative essay）時，我們經常提到文章應要包括thesis statement（主題段落）的重要性。簡單來說，thesis statement是整篇文章的靈魂，因為它宣佈作者對某一特定主題的立場。在今天的討論中，我們將首先看看thesis statement中的主要的components，然後，我們將簡要討論學生在撰寫該段落時所犯的常見錯誤。
須寫明立場主題及發展
一個thesis statement應包括文章主題（topic）、作者的立場（writer's stance），以及發展或預覽計劃（a preview or a plan of development）。在檢查以下示例時，您會更理解何謂好的thesis statements：
Contrary to some people's views, I believe memorization plays an indispensable role in our acquisition of new knowledges and maintaining our mental health.
在上面的例子，文章的主題是memorization的重要性；作者對memorization的態度（stance）是積極，正面的；作者將會從acquisition of new knowledges及maintaining our mental health兩方面去說明memorization的重要性。
牽涉範圍不宜太窄太廣
學生在撰寫thesis statement時可能會犯以下的錯誤：
1. 欠缺立場，例如：In this essay, I will discuss the importance of memorization in learning. 很明顯，這句子缺乏明確的立場。
2. 範圍太廣，文中不會有足夠的空間來闡述，例如：All examinations should be abolished. 「所有考試」真是太過闊，難以闡述。
3. 範圍太狹窄，例如：Close to 20 people got injured in the recent firebomb attack. 明顯地，這個statement只說明了一個事實，它的範圍太狹窄，無法進一步闡述。
Exercise
The following are the topic sentences taken from the three body paragraphs of an argumentative essay. Read them and answer the questions below.
Topic sentences of the three body paragraphs:
(1) With objective data derived from Territory-wide System Assessment (TSA), they enable participating schools to improve on learning and teaching in schools.
(2) Teachers can better understand the curriculum and enhance their professional knowledge in the process of participating in the TSA.
(3) TSA allows the government to evaluate the effectiveness of its education policies.
Questions
1. What is the topic of this argumentative essay? TSA or the significance of TSA.
2. What is the writer's stance?
The writer supports TSA.
3. Write a thesis statement based on the above information.
TSA is advantageous to our education system in terms of enhancing various schools' standards, improving teachers' professional knowledge in its implementation, and helping assess the government's education policies.
■Dr. A. Chan，哲學博士，哲學碩士，英語講師。熟悉公開考試之出題模式與評分準則，任教英語。
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