60 Science Research Writing If you start with a general overview or even a general paragraph about what was done and used, it can then be broken down to produce the details. However, if you begin with the details, you force the reader to put those details together to create a general picture of what you did and used. Th is is quite diffi cult for the reader to do and it is not his/her job; it is your job as a writer to arrange the information in an appropriate order so that it is easy for the reader to process it. Furthermore, asking your reader to put details together to create a picture of what you did is risky, because each reader may create a slightly diff erent picture of the process if they begin 'bottom-up' with the details, rather than 'top-down' with a general overview. When you write using 'top- down' strategies you are in control. If you begin with general statements about what was done/used (In all cases, Most sites), you and your reader share the same framework, so when you fi ll in the details you are creating the same picture of what was done/used in the mind of each individual reader. Remember: show your reader the wall before you begin to examine the bricks. In Sentence 2 'Th e sites were selected from the London Basin area, which is located in the south-east of England and has been frequently used to interpret groundwater evolution.2–4 the writer provides background information and justifi es the choice of location by referring to previous research. Why do I need to justify or give reasons for what I did? Isn't it obvious? Your reasons may be obvious to you, but they are not always obvious to your readers. If you fail to provide justifi cation for what you did, then the reader may not accept the validity of your choices. Th ey may wonder why you did things in a particular way, or why you used a particular procedure. Th is has a negative eff ect: if you don't explain why you did things then readers cannot be expected to accept your methodology, and this will eventually aff ect the way they evaluate your whole paper. Many writers believe that this section is just an impersonal description of what was done or used; in fact there is a strong persuasive and communicative element. We see this not only in language such as thoroughly or with care but also in the frequency of justifi cation. In this
Methodology — Writing Task 61 description of your materials and methods, you need to communicate not only Th is is exactly what I did/used but also I had good reasons for those decisions. Justifi cation enables the reader to trust the choices you made. Sometimes background information is given in the Present Simple to justify choices made. For example, you may have chosen a particular material because of its properties; if so, say what those properties are (Th is material is able to...). You may have chosen specifi c equipment or soft ware because of what it can do; if so, say what that is. In Sentence 2, we understand that the writer chose this geographical area because it had been previously validated as an appropriate location by other researchers. In Sentence 3 'A total of 18 samples was collected and then analysed for the isotopes mentioned earlier' the writer provides an overview of the procedure/method itself. If I gave a general overview at the start of this subsection, why should I also give an overview of the procedure itself? As you saw in Section 1.2.4, the beginning of a paragraph oft en signals the beginning of a new topic, and providing an introductory sentence is a reader-friendly technique. In addition, the overview in Sentence 3, like the one at the start of the subsection, enables the writer to move in a 'top- down' direction by creating a general framework into which the details can be easily slotted. Because the reader knows from the start how many samples were tested and what was done with them, both reader and writer share the same clear picture. Th ese sentences oft en start with phrases like Most of the tests or In all cases (see the vocabulary list in Section 2.4.2). In Sentence 4 'Samples 1–9 were collected in thoroughly-rinsed 25 ml brown glass bottles which were fi lled to the top and then sealed tightly to prevent contamination.' the writer provides details about what was done and used and also shows that care was taken. How much detail do I need to provide? If you're not certain that all readers are familiar with the precise details of your methodology, it is better to give slightly too much information than