关键词索引是指把文献的题目、正文或文摘中具有实际意义的语词抽出,作为索引款目的标目,并按其母顺序排列起来的索引。它作为一种检索工具广泛使用,已有二十多年的历史,早在1958年,卢恩等人利用计算机编制了KWIC索引并获得成功,这是人们在实现索引编制工作自动化方面最早的尝试,后来人们在此基础上又经过多次修改,出现了一些KWIC索引的改良种,那么,它们的特点、作用是什么?本文通过对美国《化学题录》、《生物学文摘》和《化学文摘》中关于键词索引的分析比较,回答上述问题。一、《化学题录》关键词索引的特点美国化学会1961年创办的《化学题录》(简称CT)使用的是KWIC索引,也叫“上下文关键词索引”其格式如下: Keyword index refers to the topic of the document, the text or abstracts of the actual meaning of words extracted as the index section headings, and according to the order of their parent index. It has been widely used as a search tool for more than two decades. As early as 1958, Loon et al. Used computer to compile and successfully use the KWIC index, which is the earliest attempt by people to automate indexing work Later, on the basis of this, people made many revisions and some improved varieties of KWIC index appeared. So what are their characteristics and functions? By analyzing the chemical title, biology digest and chemistry Digest “on the keyword index analysis and comparison, answer the above questions. First, the characteristics of the chemical index ”keyword index“ American Chemical Society founded in 1961, ”Chemical Title“ (referred to as CT) uses the KWIC index, also known as the ”contextual keyword index" in the following format: