對照(contrasting)兩個過程或事件: (contrasting two processes)

論文寫作時常需對照比較兩個事物或過程，用以突顯兩者之間的異同。請先看以下的範例段落: 

l  範列:

1. The forming of community in university courses in the U.S. probably ranges between two types of processes: a dialectic process and a rhetorical process. 2. On the one hand, a dialectic process is a way of forming community that proceeds by question and answer and involves the participants in a process of refutation and mutual discovery. 3. This kind of community is most likely formed between specialists. 4. A rhetorical process, on the other hand, is a way of forming community that for one reason or another does not involve participants in a process of refutation. 5. This is more likely formed between students and instructors in lectures and seminars.

在美國大學中形成社群可能有兩種過程: 辯證過程和修辭過程。在一方面，辯證過程是以提問和回答以及反駁和相互探討的方式來形成社群。此種社群最有可能是由專家所形成。另一方面，修辭過程是以參與者不會提出反駁的方式形成。這種社群較有可能是由學生和教師在講課和專題討論中形成。 

l 講解:

1. The forming of community in university courses in the U.S. probably ranges between tow types of processes: a dialectic process and a rhetorical process.

在段落的寫法上可在首句就先寫出是哪兩種事物的對照，例如上例中的第一句就先指出美國大學形成學術社群的兩種過程(two types of processes)為辯證過程和修辭過程(a dialectic process and a rhetorical process)，而句中動詞使用range顯得簡潔生動，值得學習使用。 

2. On the one hand, a dialectic process is a way of forming community that proceeds by question and answer and involves the participants in a process of refutation and mutual discovery.

接下來分別介紹這兩種過程，第二句先使用連接副詞on the one hand引介出第一種的辯證過程，讀者就會預期之後還會有on the other hand來引介第二種過程，這是論文寫作中常用的標記字(signal word)。 

3. This kind of community is most likely formed between specialists.

第三句是承接第二句的句意，繼續對第一種的辯證過程作說明。 

4. A rhetorical process, on the other hand, is a way of forming community that for one reason or another does not involve participants in a process of refutation.

第四句果然出現片語on the other hand來引介出第二種的修辭過程，不過是插入在主詞a rhetorical process和動詞is之間，這樣寫法顯得比較有變化，不然用on the other hand作為句首也可以，形成On the other hand, a rhetorical process is a way of ….的句子。 

5. This is more likely formed between students and instructors in lectures and seminars.

第五句是承接第四句的句意，繼續對第二種的修辭過程作說明。 

總之，這個用以表達兩事物間對照的段落是論文寫作中常採用的平行(parallel)結構，除第一句是概述外，之後的第二、三句與第四、五句都是相互平行對仗，讓全段讀起來很清楚，而且使讀者容易預期接下來要讀到的內容可能是什麼。 

l 句型:

由以上段落分析，兩種事物對照比較的段落寫法最基本的架構可由五個句子組成，以A與B的對照為例，首句先寫出A與B要作對照，第二句和第三句介紹A，而第四句和第五句介紹B，可歸納成以下的句型:

1.      ______ ranges between two types of _______: ____A___ and ____B___.

2.      On the one hand, ____A___ is a way of _______.

3.      This kind of  ____A___ is most likely 承接上一句的句義，繼續說明A的特性.

4.      ____B___, on the other hand, is a way of _______.

5.      This is more likely 承接上一句的句義，繼續說明B的特性.