5． 分类法(classification)
        　　
        在阐述某一概念的段落中，常用分类法。通过对概念中所包括的事物进行分门别类，分别加以叙述，使读者有更为清晰的认识，如：
        　　
        Ever since humans have lived on the earth, they have made use of various forms of communication. Generally, this expression of thoughts and feelings has been in the form of oral speech. When there is a language barrier, communication is accomplished through sign language in which motions stand for letters, words and ideas. Tourists and the people unable to hear or speak have had to resort to this form of expression. Many of these symbols of whole words are very vivid and exact and can be used internationally; spelling, however, cannot. Body language transmits ideas or thoughts by certain actions, either intentionally or unintentionally. A nod signifies approval, while shaking the head indicates a negative reaction. Other forms of nonlinguistic language can be found in signal flags, Morse code, and picture signs.
        　　
         在该段中为了说明topic sentence中的 "various forms of communication"，作者将其分为oral speech, sign language, body language及other forms of nonlinguistic language，并逐加阐述。
        　　
        采用这种方法的段落并没有标志突出的连接词，所述各项均为平行并列关系，所以没有明显的主次之分。