Definition and Length of Abstract
An abstract is a brief,accurate and objective representation of the essential content of an article,a paper,book,speech,report,dissertation,patent,standard,or other work,presenting the main points in the same order as the original without any added interpretation,comment or criticism.It can exist independently as a miniature of the original text.It is the last item that you write,but the first thing people read when they want to have a quick overview of the whole paper.
An abstract is important because it gives a first impression of the document that follows,which lets readers decide whether they want to continue reading and showing them what to look for if they do.Though some abstracts only list the contents of the document,the most useful abstracts tell the reader more.An abstract should represent as much as possible of the quantitative and qualitative information in the document and reflect its reasoning.
An abstract can be informative,indicative,critical,or written from a particular point of view.In essence,abstract informs the readers of part or all of the seven bits of information below:
1.1 Background
What is the topic in the paper?Meanwhile,it will also cover the question such as what previous researches have been made.
1.2 Aim or Purpose
What is the author's reason for writing?It may involve the main objectives or main ideas.
1.3 Particular Focus or Interest
What is the author's focus in this piece?It will illustrate the main issues that the author concentrates his or her attention.
1.4 Method
What kinds of evidence does the author provide?At the same time,how does the author try to convince the reader of the validity of his/her main idea?
1.5 Findings or Results
What are the consequences of the problem or issue that the author is discussing?The author may demonstrate his or her main findings or results.
1.6 Recommendations
What solutions does the author present to the reader to resolve the problem or issue in the piece?It is quite often that the author may give his or her recommendations here.
1.7 Conclusions,Implications or Significance
Does the author describe a“cause and effect”relationship or explain the origins of this issue or problem?What conclusions does the author draw from his/ her study of the issue or problem?Perhaps,what implications or significance does the author's study bring to some fields?
Normally，an abstract does not include any information that is not in the document itself,nor tables and diagrams or citations from other people's work.
A good abstract is often distinguished by the following elements:It is acceptable to use one or more well developed paragraphs,which are unified,coherent,concise, and able to stand alone.Also,it is good enough to use an introduction-bodyconclusion structure which presents the article,paper,or report's purpose,results, conclusions,and recommendations in that order.Remember to follow strictly the chronology of the article,paper,or report.If necessary,it is necessary to provide logical connection between the information included.Sometimes,it is essential to use passive verbs to downplay the author and emphasize the information.
Anyway,there may be no fixed length for an abstract.It depends on what type of abstract is written.In addition,different journals usually establish different word limit for the abstract that the author can't exceed.For example,the abstract length should be 3%of the whole paper in Biological Abstract,and 5%in Astrophysical Journal and Physical Review.The abstract of a paper with 5 pages should not exceed 125 words and even the largest length should not be more than 1,200 words in Revue de Geologic. For all this,it is important to write enough for what the reader needs to know rather than summarizing everything in the paper.A typical length is between 100 and 250 words,or between 5%and 10%of the original content.