Some Guidelines on Report Writing

Transcription

1 Some Guidelines on Report Writing FORMAT FOR 1 ST YEAR LAB REPORTS: Your report should state clearly at the beginning your name, the date and the title of the report. Most scientific reports (generally called 'publications' or 'papers') are divided into sections, and you are advised to follow this convention and to divide the body of your Report into sections, such as: Introduction, Experimental Method, Results, Discussion, and Conclusion. Reports should be prepared using a word processor and submitted both on paper to the lab office and electronically online via Turnitin. Plan your report writing and ensure that you give yourself sufficient time to produce a well polished result. Also leave time for technical hiccups in the printing and online submission. We do not accept my file got corrupted/deleted or the printer would not work as adequate excuses for late reports. Part of being professional is giving yourself a realistic work timetable which allows for unforeseen problems. LENGTH OF REPORTS: The reports for cycles 1 and 3 should be between 4 and 6 pages of A4 (~1500 words) for the main body of the text; graphs, figures and tables can be extra. The report should be stapled together with a Report Form as the first sheet. The shorter the report the better, provided that it conveys the required information and is written in good English. Quality is far more important than quantity: you can get good marks on a short report if it is done well. Long reports frequently reveal uncertainty about what is relevant and can generally be improved by editing. ABOUT REPORT WRITING: 1. Why do Physicists need good report writing skills? In science it is critical that we are able to communicate to others what we have done, why we did it and what we have seen. The two major methods we use to tell others of our work are publications in scientific journals and presentations at conferences. In fact, in any professional career you will discover that the written report is essential for documenting your progress and communicating it to other people. 2. What should a written report achieve? Our aim when we write a report should be to inform the reader in as clear and concise a way as possible. Most new students find this difficult to achieve without some guidance and a good deal of practice. In some cases you will also need to unlearn bad habits you have acquired at school. The style and structure of your report have a great impact on its readability and the ease with which the reader can extract the useful information it contains. For this reason, there are particular writing styles and report structures that you should use. It is also important to remember when writing at the degree level, simply saying what you did is not enough. You also need to explain what you did, why you did it, and what the results mean. Blackett Laboratory, Imperial College London 115

2 Writing good scientific reports and papers is an acquired skill and one of the chief aims of the First Year Laboratory course is to introduce you to this important discipline. As with most exercises of this type you will need to practise before you begin to produce work of a really high standard. There are as many different ways of writing a report as there are people to write it. We all have different writing styles and preferences. As a result it is impossible to tell you exactly how to write your own reports: you will have to discover for yourself the methods you find best suited to putting your own ideas across. There are, however, a number of broad guidelines you should follow. While we cannot give an exact template for your lab reports we can offer some very specific advice on what not to do. Throughout this document we give clear advice on things to avoid. We suggest that after having written your first lab report in draft form you use this document as a check-list to see if you have fallen foul of any of these pitfalls and then make the necessary adjustments in your final draft. This process of drafting and grooming is essential. Hardly anybody is capable of producing a perfect scientific report in a single draft and you should not expect to be able to do so. Your reports should tell a coherent story, leading the reader through abstract, introduction, method, results and discussion in a logical manner. To achieve this, reports should be written in good English throughout, making proper use of complete sentences, paragraphs and so on. 3. Look at journals in the library To get a better idea of how professional reports are presented, take a look at some of the journals in the library or access them on the web. For example, Physical Review Letters (PRL for short) is one of the premiere physics journals. The papers in PRL tend to be very short, and most will contain some concepts you have not come across before. What you should discover when you read one of these papers is that the introduction and much of the method will be written in a way that you can follow (though you may not understand all the words). These papers will almost always give you some clearly presented general background before diving into detail, and aim to explain results and concepts with clarity and elegance. Read the editorial by Reinhardt Schuhmann, Phys. Rev. Lett. 100, (2008) for some very useful tips on the purpose of articles and good scientific writing. Good papers have been edited and re-written many times, not simply put together all in one go. Note: Articles in PRL are very short and so do not have section headings. Even though your lab reports are perhaps even shorter than a PRL article you must use section headings (for practice). 4. Being assigned a report title In the last session of the long experiments your assigned demonstrator will discuss with you suitable report topics and set you a title. This should be based on what you have achieved in the lab, but it is important to note that you can get full marks for the report even if you have not finished the experiment. Marks for reports and lab work are assigned separately. You will also be given a cover sheet, which should be firmly attached to the front of the report. This will state the date by which the completed report should be handed in to the first year lab office. Your demonstrator should return your reports to you after marking, and discuss any comments they have with you. Blackett Laboratory, Imperial College London 116

3 5. Late reports Reports should be handed in to the 1Y lab office by 4pm on the R2 date set on the report cover sheet. All reports are date stamped when they arrive. Late reports will be awarded zero marks, so please ensure you upload an electronic copy to Turnitin and submit your paper copy in good time. 6. In what style should you write? Scientific reports are almost always written in an impersonal and somewhat detached style, the oscilloscope was connected to the signal generator rather than I connected the oscilloscope to my signal generator. A good general rule is to avoid the first person (I/we) altogether. There are some exceptions to this rule, for instance, if the results are open to several different interpretations you might say we believe these results show. rather than this shows that.. For first year lab reports you should assume that the reader of the report is a physicist with the same knowledge as your classmates, but that they do not have a detailed knowledge of the experiment you are writing up. The Schuhmann editorial gives some good advice about structure:... a readable manuscript should have a logical structure similar to that in any narrative. A short story, for example, sets the scene and the characters, presents conflict, provides a resolution, and ends with an epilog. These same elements make up a well constructed scientific article. It also should be an interesting narrative, although the terminology is different. To set the scene, a scientific narrative begins with an introduction, to explain where the field stands at present. Conflict appears in the form of an unsolved problem, and resolution as the solution to the problem: the result. The epilog becomes the summary, which discusses the meaning of the result, to give readers some idea of its repercussions. 7. How long should a report be? For reports on the long optics and electronics experiments you should aim to write about 4 to 6 sides of A4 text in addition to large figures and tables. You should avoid writing much more than this as the demonstrator who marks it is not obliged to read beyond this page limit. It is quality not quantity that is important. For the report on the projects you will carry out at the end of the first year a rather longer write up may be more appropriate. 8. How should a report be structured? 8.1 Title, Author list and Dates There is a particular structure that you will find used in most research publications and reports. Whilst not set in stone, this structure can be a very useful guide when writing your own reports on laboratory experiments. A report begins with a title, name of authors and date. In your case the front sheet used for marking is not sufficient for this purpose, and you should have these details on the first page of the report proper. Blackett Laboratory, Imperial College London 117

4 8.2 The Abstract Usually the title and author list will be followed by an Abstract. The abstract is a very brief and concise summary of the report. It should mention any important methods used, final results, and your conclusions. It should not however go into any detail, and around words are generally sufficient. The aim of the abstract is two fold. First, it sets the scene for the bulk of the report, highlighting important points that the reader should take note of when they read the full text. Secondly, a very large number of papers are published in some subjects, and the abstract helps to tell a potential reader if a particular paper is of interest, without having to digest the whole thing. Abstracts are often kept electronically so they can easily be searched. An example abstract : The wavelength of light emitted by a commercial diode laser used in a compact disc player has been measured using a commercial spectrometer. This device employs a diffraction grating with 1800 lines/mm. The wavelength emitted. 8.3 The Introduction The next section is the Introduction, in which you should give a full description of why you carried out a piece of work, what the underlying physics effects are, and give a brief description of any theoretical background. You do not need to go into lots of technical detail on the apparatus, for example, but you should explain what the key pieces of apparatus are, why you used them, and what you hoped to achieve. When the reader gets to the more technical points later on in the report they should then have an overview of what you were trying to accomplish, and will be much more likely to understand and appreciate the relevance of these details. For example if you set out to measure the pulse length of a laser with a photodiode you would say this in the introduction. Then when your reader encounters a description of how you set up a photodiode, what amplifier and power supply you used and so on in the experimental section they will know why you are talking about this. When writing this section you should also avoid copying out large parts of the lab script. Often the present tense is appropriate for an introduction e.g. Spectroscopy is an essential technique in modern astronomy Don t use the future tense e.g. The theory of this process will be presented in the next section. Instead say e.g. The theory of this process is described in section Theory If some extra theory is required then this section generally follows the introduction. You should explain what equations and symbols mean and try to give a physical picture of what they describe. Simply writing some equations and expecting the reader to follow them without any explanatory text is not sufficient. Again, the present tense may be appropriate here e.g. The angular velocity of the wheel is given by... Don t write out every step of a derivation. Write just enough that a hypothetical reader (drawn from your peers) would be able to reproduce the intermediate steps. 8.5 Experimental Method Introduction and theory sections are generally followed by an Experimental or Method section. Here you can get quite technical, having set the scene for the description of Blackett Laboratory, Imperial College London 118

5 your apparatus and method in the introduction. Make good use of labeled diagrams and figures to explain what equipment you used and how it was set up. This is one of the best places to impress your demonstrator with your understanding of the experiment. When you say what you did, also say why. If you make a particular point of something in the set up, say why you did it that way. If you encountered any problems or errors in the equipment this is also a good place to discuss them. Standard items of equipment such as oscilloscopes do not need to be described in detail, and again you should avoid simply copying out sections of the lab script. This section should be written in the past tense and in the passive voice e.g. The pendulum was displaced from the equilibrium position by 2 cm and tied in place with a piece of cotton. Never use the kind of cook book style adopted in many lab scripts. (i.e. don t use the imperative, don t instruct the reader what to do). Connect the photodiode to the oscilloscope and make a note of the voltage is not appropriate for a laboratory report. You are writing a report, not a lab script! 8.6 Results, Errors and Discussion Any numerical result you put in your report is meaningless without both units and an uncertainty. It is generally more useful and informative if you mix your presentation of results, error calculations and the discussion of results in one section. Don t include detailed formulae describing how the errors were calculated unless there is some important or subtle point you need to make. On the other hand, do include a few sentences describing how errors enter your experiment and whether these errors are systematic or random. 8.7 The Conclusion Finish the main text of your report with a Conclusion. The conclusion should be a self contained entity, and you should briefly restate the aims of the experiment and method used in a few lines to remind the reader of the background to your experimental results. The main job of the conclusion is to draw all the elements of the report together, point out its successes and failures, to say what you have achieved and learned and how the experiment could be improved. Avoid making subjective or personal statements like the experiment was a great success and I learned how to use an oscilloscope.. The reader doesn t really care if you enjoyed the experiment. Lab reports are not novels or short stories. They are allowed to end rather abruptly with rather flat factual statements. 8.8 Bibliography You will almost always find a bibliography in a research publication or reference work. The aim of this section is threefold. To act as a source of background reading and information for the interested reader, to provide proofs for specific pieces of information vital to your case, and to acknowledge those from whom you have drawn ideas and inspiration. The usual way of referencing a paper or book in the text is to use a number following the statement [1]. In the bibliography you can give the full source, for example: [1] A. N. Other. The Bumper Book of Integrals. Cambridge Scientific Press (1995) You can look at research papers in some of the journals in the library for more examples of how to reference other peoples work. Some may reference by author name and date in the text rather than by number. Blackett Laboratory, Imperial College London 119

6 8.9 Appendices Occasionally you might want to include additional detail on, for example, the derivation of theoretical results, a listing of a computer program or other bulky item that would break up the flow of the report. In this case you can put an appendix including this detail at the end of the report and refer to it in the text. Don t put important graphs of results in an appendix. Your data are of prime importance and should appear in the main body of the text Alternative Structures Remember the cardinal rule; make life easy for your reader. In some cases a slightly different ordering of your material may be appropriate i.e. the following might be an appropriate model for a series of related but distinct experiments Title, Abstract Introduction Theory Method (expt. 1) Results, Errors, Discussion (expt. 1) Method (expt. 2) Results, Errors, Discussion (expt. 2) etc. Conclusions Bibliography Appendices 8.11 Computing Reports Lab reports for computing should follow the same general structure as for a more practical experiment, but there are subtle differences in what the relevant sections should refer to. The title, abstract and introduction all serve the same purpose as in the description above. The theory section should describe the idealised mathematical or physical background to whatever you are reporting on. This might provide analytical equations for a physical system that is going to be simulated, or a discussion of the analytical results that are going to be approximated by the computer. The most significant differences arise in the discussion of the experimental method. Here, rather than giving a discussion of the apparatus, you need to discuss the algorithm you have used to take the physical or mathematical problem, discussed in the theory section, and allow it to be simulated or evaluated on the computer. You also will need to discuss how that algorithm was implemented on the computer. This does not mean that you should detail every line of code - this is bad practice and should be avoided. Instead you should discuss the generalities of the method rather than the specific implementation. Flow diagrams are very useful for this, and are generally much easier to understand than explicit descriptions of code, or written descriptions of an algorithm. You should, however, include relevant code listings in an appendix to your report. The results, analysis and discussion sections are broadly similar to those of other reports, with the exception of the uncertainties section. For this you will need to consider Blackett Laboratory, Imperial College London 120

7 the limitations of the algorithm you are using, any approximations (eg. small angle approximation) made in deriving the maths behind the algorithm, possibly numerical rounding errors and how these affect the final results. In some projects, comparison of a precise solution to the problem (eg. an analytical determination of an integral) to what has been produced by a computational method is a central part of the results. Conclusion and bibliography should be handled in the same manner as other reports, while listings of relevant code should be included as an appendix. 9. Appendix. Dos and Don ts Start your report with a title, name and date. Start each new section with a sentence. Don t start a new section with a figure or a table. A well structured report is vital if you want to present your results in an understandable and entertaining way. Think about what you are going to write and draw up a rough outline before you start writing the report proper. Use good English throughout. Avoid giving a blow by blow account. Do not write (a) I connected wire 1 to Pin 7 and 5. (b) I turned on the power supply. (c) I connected the LED Keep your writing in the third person and avoid unnecessary detail. Resist the temptation to get carried away spending ages on a beautiful visual format of your presentation. The clarity of your writing will be much more important. Avoid lists (e.g. of apparatus) and bullet points (these can be useful in some contexts, like here, but are not really appropriate for a lab report). Don t get carried away with fancy fonts. A lot of this kind of thing is actually distracting. Your goal should always be clarity. Indent paragraphs or leave an empty line to delineate a paragraph. If you use an abbreviation, give its meaning in full the first time you use it. For example: A digital multimeter (DMM) was used to measure the root mean squared (RMS) voltage across the capacitor. A second DMM was used to measure the RMS voltage across the resistor. Logical and numerical symbols can be used in equations, but they should not take the place of words in the bulk of the text. Use perpendicular rather than, absolute rather than Abs for example. If your word processor cannot produce what you need (e.g. Greek letters or mathematical symbols) then leave a space and write it in by hand rather than using something which is incorrect. For example, if your word processor cannot render don t be tempted to write 3*10^8. This is not acceptable. If you write out an equation, explain what all the terms and symbols mean. For example: The reactance Zc of the capacitor C is given by Zc = 1/ωC, (1) Blackett Laboratory, Imperial College London 116

8 where ω is the angular frequency. Now when you talk about Zc it is clear what you mean and how it is related to other quantities *. If you use more than one or two equations you should number them to make it easier to refer to them in the text. If you then refer to these symbols later on in the text, when the equation is no longer visible (many pages later), you might define them again if it is likely to help the reader understand what you mean. When you give a numerical result it is meaningless without giving both units and an uncertainty. The speed of light is 3.0 tells you nothing useful. The speed of light is 3.08 ± 0.01 x 108 ms -1 is much more meaningful. Note that the value and its error are given in the same units, and to the same power of 10. Use an appropriate level of precision when you quote results. c = ± x 10 8 ms -1 gives lots of essentially useless or even misleading digits. Uncertainties are generally quoted to one or two significant figures. It is pointless to quote a result to more significant figures than allowed for by the error. It is much more useful to include diagrams, figures, graphs and tables in the text where you can see them when they are being discussed than to place them all at the end of the report. Making the reader flick backwards and forwards to see what you are talking about can be both annoying and distracting. Tables and figures should have a number and a caption. This will make them easier to refer to in the text. The reader will not look at a figure until instructed to do so in the text. The caption may be very brief e.g. Figure 1. Plot of current I against voltage V for a range of values of resistance R. In general it is wasteful and redundant to both plot a graph and give a table of the same results, unless you want to make a particular point about some of the numerical values recorded. Tables of numbers belong in your lab book, not in your report. If you are tempted to include a table, try instead to think about a way to represent the data graphically. When plotting a graph at least some of the points should be accompanied by error bars to give a clear visual representation of the error in your measurement. Don t forget to label the graph axes and include units. Leave time to proof read your report at the end. * Notice also that the equation is punctuated as a part of the sentence that surrounds it. where is not capitalized. Blackett Laboratory, Imperial College London 117

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