22 Science Research Writing go backwards and forwards, beginning each sentence in the literature review with However or On the other hand! • general/specifi c: Start with general research in the fi eld and gradually move to research that is closer to your own. When should a research reference come in the middle of the sentence? When it is necessary to avoid confusion, for example if you are referring to more than one study in a sentence or if the citation reference only refers to part of your sentence. You can see examples of this in Sentences 6 and 7. In Sentence 7 'However, although the eff ect of the rubber particles on the mechanical properties of copolymer systems was demonstrated over two years ago,8 little attention has been paid to the selection of an appropriate rubber component.' the writer describes a gap in the research. Th is is where you begin to introduce the purpose of your paper and the specifi c problem you will deal with, and in order to do this it is necessary to create a research space. You can do this either by describing a problem in the previous research or by indicating that there is a gap in the research. It is conventional to introduce it with a signalling connector such as However or Although. In professional writing it is unusual to put it in the form of a question; instead you can state it as a prediction or a hypothesis which you intend to test. Don't be shy about pointing out the problems in previous research. In the fi rst place it may be necessary in order to explain why you have done your study, and in the second place, the language used here is usually respectful and impersonal, and is therefore not considered off ensive. We will look at the politeness aspect of this language in the vocabulary section at the end of the unit. You may need more background information at this stage (for example, you may need to give details of the properties of the material which you have chosen to investigate, or describe the specifi c part of the device which you plan to improve). Research writing requires far more background information than you have previously given in your undergraduate writing, and it is better to off er slightly too much background information than too little.
Introduction — Writing Task 23 In Sentence 8 'Th e present paper presents a set of criteria for selecting such a component.' the writer describes the paper itself. At this stage you move to the present work. You can describe it, say what its purpose or focus is, give its structure or a combination of these. Check Section 1.2.3 to see whether to write these sentences in the active or the passive. You normally use the Present Simple tense to describe the work itself (Th is paper is organised as follows or Th is study focuses on) and the Past Simple tense to talk about the aim of the work (Th e aim of this project was...), because in 'real time', the aim occurred before the work was carried out. It is also possible to state the aim in the Present Simple (Th e aim of this work is...). Th is is especially true in cases where the aim is only partially achieved in the paper you are submitting and the rest of the work will be done and reported on at a later stage. In Sentence 9 'On the basis of these criteria it then describes the preparation of a set of polymer blends using PLA and a hydrocarbon rubber(PI).' the writer gives details about the methodology reported in the paper. In Sentence 10 'Th is combination of two mechanistically distinct polymerisations formed a novel copolymer in which the incorporation of PI signifi cantly increased fl exibility.' the writer announces the fi ndings. Although you can give information about your methodology or fi ndings in the Introduction, be careful not to go into too much detail at this point or you will fi nd that you have nothing to write about in the Methodology or Results sections. Look at the way the writer begins Sentences 9 and 10. In each case the information is joined to the previous sentence with a pro-form (On the basis of these criteria in Sentence 9 and Th is combination in Sentence 10).