1、ObjectivesLearn how to write a technical abstract:Types of abstractsFormats of abstractsTenses used in informative abstractsGuidelines for writing informative abstracts Purpose of an AbstractThe abstract provides the reader with a brief preview of the study based on information from the full report.
2、It fulfills two major purposes.Selecting:allow readers who may be interested in the full article to quickly decide whether it is worth their time to read it.Indexing:being used independently as a substitute of the research paper in the database or index for paper retrieval.I.Types of AbstractsAccord
3、ing to their functions and contents,abstracts can be classified in three types:descriptive abstracts,evaluative abstracts and informative abstracts.1.Descriptive Abstracts 说明性摘要说明性摘要A descriptive abstract indicates the type of information found in the work.It merely identifies the areas to be covere
4、d in the report.It is an extended statement of purpose or scope,but makes no judgments about the work,nor does it provide results or conclusions of the research.说明性摘要是对作品信息类型的提示，它只指出报告所覆盖的范围。它是对目的与范围的延展性陈述而对作品不做评判也不提供研究结果与结论。An example of an descriptive abstractThis report analyzes the principles of
5、 magnetic refrigeration with application to air conditioning.A comparison with the conventional evaporation-condensation gas cycle device is presented.The applicability of magnetic refrigeration to air conditioning is discussed.该报告分析了磁制冷用于空调的原理。与传统的蒸发凝聚气体装置进行了比较。对于把磁致冷应用于空调进行了讨论。The descriptive abst
6、ract merely states what the full report contains.After reading the abstract above,you get to know what this article is about,but to learn the main idea,you must read the entire article.2.Evaluative Abstracts 评论性摘要评论性摘要An evaluative abstract is also called a critical abstract.Its primary purpose is t
7、o analyze the accuracy,completeness,usefulness,appeal,and readability of an article(分析文章的准确性、完整性、有用性、趣味性和可读性).The evaluative abstract emphasizes the writers assessment of the original work.In the evaluative abstract you can include your own comments and reactionsyour thoughts and feelings regarding
8、the material and its presentation(你对内容及其表达方式的意见).An example of an evaluative abstractThis article presents four strategies for reading technical information effectively.The article is both interesting and instructive,with each strategy described in detail and with examples.本文叙述了有效地进行专业信息阅读的四种策略。文章既有
9、趣味性又有知识性，对每一种策略都进行了详细叙述并举例说明。In this abstract,the first sentence is descriptive.In the second sentence,the phrases“both interesting and instructive”and“in detail and with examples”give the writers assessment of the original article but not the content or the main idea of it.Such type of abstract is
10、usually used in book reviews.3.Informative Abstracts 报道性摘要报道性摘要An informative abstract summarizes the entire report and gives the reader an overview of the facts that are laid out in detail in the paper itself.It presents and explains briefly the main points of the article,including the background,p
11、urposes,methods,results,and conclusions.报道性摘要总结整个报告，对论文中详细铺陈的事实给予概览。它呈现并简要解释文章要点，这包括背景、目的、方法、结果和结论。An example of an informative abstract1It is generally believed that food habits of closely related species do not overlap significantly where species occur together.2The objective of the study was to t
12、est the theory of competitive exclusion.3The food habits of larval butterflies of two related species from a zone of overlap near Oil City,PA were examined.4Transects in five different habitats were used to determine food and habitat preferences in wild populations.5Two species of captive caterpilla
13、rs were offered various foods in the laboratory;weight changes of foods and caterpillars were determined daily.6Food habits in overlapping habitats were significantly different between the two species(p=0.001).7Food habits in non-overlapping habitats were not significantly different(p=0.52).An examp
14、le of an informative abstract 8There were no differences in food preferences(p=0.76)or growth rates(p=0.88)on different foods in laboratory maintained populations.9These species are able to coexist because they are not competing for the same,and limiting,food resources in the same area.10These resul
15、ts support the theory of competitive exclusion because the two species did not use the same food resources from similar habitats.An example of an informative abstract通常认为，生活在同一地域的亲密相关物种的食物习性是不会明显地相互重叠的。该研究的目的是检验竞争排斥理论。对有亲缘关系的两种蝴蝶幼虫的食物习性进行了研究，这些幼虫来自宾夕法尼亚石油城附近的一个部分重叠地区。使用五个不同栖息地的样带（用于观察实验的地带）来确定野生群体的食
16、物和栖息选择。在实验室里给捕获的两种蝴蝶幼虫提供各种不同的食物；每天都确定食物和幼虫的重量变化。在重叠栖息地的两种幼虫的食物习性有明显差异。在不重叠栖息地的两种幼虫的食物习性没有明显差异。在实验室喂养的蝴蝶幼虫中，在对于不同食物的选择或生长速率方面没有明显差异。这些物种可以共生是因为它们没有在同一地区为相同的、有限的食物来源而竞争。这些结果支持竞争排斥理论，因为这两个物种在同一栖息地不使用相同的食物资源。II.Formats of Informative AbstractsAccording to their formats,informative abstracts can be class
17、ified into three kinds:Standard abstracts Structured abstracts Reduced abstracts1.Standard Abstracts A standard informative abstract usu.consists of the following parts in one paragraph:Format of a standard abstract:1.Background:Introducing the present situation and the question of the research2.Pur
18、pose:Stating the task,the problem to be solved,or thesis of the research3.Methods:Describing the principles,subjects,materials,technology,methods or procedures of the research4.Results:Presenting the data,effects or properties obtained from the research5.Conclusion:Providing the solution or answer t
19、o the problem raised by the purpose;giving recommendations or predictions on the basis of the resultsAn example of an standard abstract:(1)While College English Tests（CET）have promoted the college English teaching,they have also led to the test-oriented teaching in colleges and hindered the developm
20、ent of students communicative competence.(2)The objective of this study was to examine the validity and reliability of CET-4 in colleges and universities.(3)We conducted an experimental test to 62 sampled college students in December 2003,one year after they took CET-4 in December,2002.(4)A total of
21、 31 students in the control class were examined with the original paper of CET-4 2002,while 31 students in the treatment class were tested with a specially designed performance-test paper in which the multiple-choice questions were all changed into the subjective ones.An example of an standard abstr
22、act:(5)The double-blind method was used throughout the experiment to secure the objectivity of the test and the evaluation.(6)The test scores were processed with the statistical analysis system SPSS.(7)The results showed that although there was no significant difference between the experimental clas
23、s and the control class in their CET-4 scores in 2002,there was significant difference between them in their experimental test scores(P0.01).(8)The mean score of the treatment class was significantly lower than that of the control class(51.47 vs.62.55).(9)Moreover,there were significant mean-score d
24、ifferences between CET-4 in 2002 and the Retest in 2003 for both the Control Class(69.06 vs.62.55;P0.01)and the Treatment Class(67.61 vs.51.47;P0.01).An example of an standard abstract:(10)This study indicates that both the validity and reliability of CET-4 test is low,and thus it cannot objectively
25、 reflect students communicative competence.(11)To eliminate the negative washback effect of CET,we suggest that CET be devised as a criterion-referenced test,frequency of the test be reduced,subjective questions be increased,and commercialization of the test be avoided.Example analysisIn the example
26、,the first sentence introduces the background situation of the research.The second sentence states the purpose.In sentence three to six,detailed explanations of the methods are given,including the population,materials,procedures and the statistical treatment.In sentence seven to nine,the results of
27、the study are presented,including the data obtained and their meaning.The tenth sentence states the conclusion,which provides an answer to the question raised by the purpose.The eleventh sentence presents necessary suggestions for improving the CET Test.2.Structured Abstracts 结构式摘要结构式摘要Rather than h
28、aving a single paragraph,structured abstracts contain a sequence of short paragraphs with subheadings次级标题,Context(Background)背景,Objective目的,Design设计,Setting范围、地点,Subjects(Patients,Participants,or Samples)对象,Interventions处理（治疗）方法,Main Outcome Measures主要观察指标,Results结果,and Conclusions结论.The format and
29、example of a structured abstract:Context:Experiments show that dental caries rates are higher among lead-exposed animals,but this association has not been established in humans.Objective:To examine the relationship between blood lead levels and dental caries.Design:Cross-sectional survey conducted f
30、rom 1988 to 1994 that included a dental examination and venipuncture blood lead assay.Setting and Participants:A total of 24,901 persons aged 2 years and older who participated in the Third National Health and Nutrition Examination Survey,which assessed the health and nutritional status of children
31、and adults in the United States.Main Outcome Measures:For children aged 2 to 11 years,the sum of decayed and filled deciduous or primary surfaces;for persons aged 6 years and older,the sum of decayed and filled permanent surfaces;for those 12 years and older,the sum of decayed,missing,and filled sur
32、faces.Results:The log of blood lead level was significantly associated with the number of affected surfaces for both deciduous and permanent teeth in all age groups,even after adjusting for sociodemographic characteristics,diet,and dental care.Conclusions:Environmental lead exposure is associated wi
33、th an increased prevalence of dental caries in the US population.Findings may help explain the distribution of caries by income and region of the United States.3.Reduced AbstractsEditors of journal articles often establish a word limit for the abstract that authors cannot exceed.To satisfy such limi
34、tations,you can shorten the abstract by omitting the background and combining the purpose and methods into one sentence.The format of a reduced abstract:1.Purpose+Methods 目的+方法2.Results 结果3.Conclusions 结论An example of a reduced abstract:To develop students ability in autonomous English study,61 thir
35、d-year undergraduates were selected and given a comprehensive training in metacognitive,cognitive and cooperative strategies.The results indicate that there was a significant improvement in the students ability in cognitive and cooperative strategies;however,there was no significant improvement in t
36、heir metacognitive strategies.The experiment shows that the strategic training has developed students ability in autonomous study,and more concrete directions may be necessary for improving their ability in study supervision and self assessment.Example Analysis With the background sentence omitted,t
37、he first sentence of the abstract introduces both the purpose and the method,which include the subject,material and approach.The emphasis is placed on the results of the study,which consists of both positive and negative results.The third sentence contains both the conclusion and recommendation for
38、further research.Another example of a reduced abstract:To determine the bacteria causing stomach troubles,biopsy specimens were taken from intact areas of antral mucosa in 100 consenting patients presenting for gastroscopy.Spiral or curved bacilli were demonstrated in specimens from 58 patients.Baci
39、lli cultured from 11 of these biopsies were gramnegative,flagellate,and microaerophilic and appeared to be a new species related to the genus Campylobacter.The bacteria were present in almost all patients with active chronic gastritis,duodenal ulcer,or gastric ulcer and thus may be an important fact
40、or in the aetiology of these diseases.Example Analysis With the background sentence omitted,the first sentence of the abstract introduces both the purpose and the method,which include the subjects,material and technology involved.The emphasis is placed on the results of the study,which consists of t
41、he second and the third sentence and the first part of the fourth sentence.The second part of the fourth sentence serves as the conclusionan answer to the purpose of the experiment.III.Tenses Used in Informative AbstractsGenerally speaking,the background sentence is written in the present tense sinc
42、e it introduces the general situation of the research.The purpose sentence is written in the past tense to indicate that the study has been finished.The sentences of methods and results are also written in the past tense.However,if general fact or universal truth is expressed in the purpose,methods
43、or results sentences,it can still be written in the present tense.III.Tenses Used in Informative AbstractsThe conclusion sentence is written in the present tense.If the conclusion includes any suggestion or implication,a model verb such as may is used.Commonly used tenses and sentence patternsTopicS
44、entence Structure and TensesBack-ground背景背景It is generally believed that.(present tense).The method of.is widely used in.The traditional way of treating the disease is.Purposes目的目的The objective of the study was to determine whether.(present tense)An aim of our experiments was to determine if.(presen
45、t tense).As part of an effort to understand the origins of.,the present study assessed the impact of.Purposes+Methods目的目的+方法方法To determine whether.(present tense),we.(past tense)To test the hypothesis that.(present tense),we.(past tense).TopicSentence Structure and TensesResults 结果结果We found that.(p
46、ast tense).Results showed that.(past tense).Conclusion结论We conclude that.(present tense).These findings indicate that.(present tense).The findings of this study provide the evidence that.(present tense).These results support the theory of.Recommendation or Implication建议或启发建议或启发These results suggest
47、that.(may+verb).These results may provide the basis of.Continued IV.Guidelines for writing Informative Abstracts 1.Keep the Abstract Concise.摘要应简明The abstract for a journal article is usually limited to about 200 words and not more than 250 at the most.You have to restrict it to the main points of t
48、he article without including any information that is not in the original.2.Make Sure the Abstract Is Self-contained.摘要应自成体系The abstract should stand alone.It will be read in isolation when it appears in a database.Do not cite any references in the abstract,which can only be found in the main body of
49、 the research paper.3.Use a Logical Order.（与原文逻辑顺序保持一致（与原文逻辑顺序保持一致）Abstracts are usually organized in a similar way to the original paper.By following the general outline of the original document,you give the reader an idea of the organization and development of the original,which helps guide the re
50、ading of longer documents.4.Keep Results the Major Part.（以研究结果为主要部分）Readers are most interested in what you found in your research.So,in most abstracts,the results should take up most of the space.Arrange the results usually in an order from the most important to the least important.5.Give the Sampl
