Report Writing in Physics

General

To communicate effectively an author needs to be sure what information they want to convey, and have a clear idea of their target reader. The text (particularly the introduction) will depend on the background knowledge you assume your target reader will have, and also what you want them to learn from reading the report. For most undergraduate reports, the target reader is assumed to be a competent student at your own level.

The structure of sections and sub-sections in the report can vary depending on its nature and content, but they always start with an introduction and end with conclusions or a summary.

Writing the title

The title should indicate what has actually been done and should match what will be said in the conclusions. It should also distinguish between experimental and purely theoretical work. Good practice is also to include keywords that will attract potential readers, such as what was measured or the technique used.

Examples could include: 'An investigation of ...', 'An attempt to measure ...', 'Development of an instrument to ...' or 'A calculation of the effect of ...'.

Writing the abstract

The abstract is a summary of the report, designed to be published and read separately from the report. The primary purpose of the abstract is to enable someone to decide whether to read the full paper.

The abstract needs to show what was done and give any conclusions or simple numerical results obtained. If the results are more complicated, it will indicate what kind of information will be found in the report.

The abstract should be understandable without reference to any other part of the report (other than the title), and should include keywords that readers may search for. Abstracts are written in continuous prose and rarely contain an equation or reference.

Writing the introduction

The purpose of the introduction is to introduce the reader to the subject matter of the report. There are three essential components:

  1. Establishing common ground. The first sentence must be easily understood, and is often a statement of something the reader is familiar with.
  2. Describing the background and motivation for the report. This normally involves referring to earlier work, summarising the parts that are essential to understanding this report, and leaving the reader to follow up by reading the original sources if they wish.
  3. Stating what the report will do. For example, a report might be designed to describe an experiment and explain why the results are different from some already mentioned.

A reader should be able to get a general appreciation of your work by reading just the introduction and conclusion sections.

Writing mathematics

In professional scientific writing, maths is included within the rules of normal English grammar. The text is in continuous prose and can be read by treating the symbols =, >, and ≈ as verbs, or by treating the whole expression as a single object.

Large or important equations are displayed either centred on a line or indented from the left, and often identified by a number in the right-hand margin. The punctuation of the sentence is maintained so, for example, if the equation is part of a sentence then it will be followed by a comma, and the next part of the sentence continues on the next line.

Small equations are often included as part of the flow of the text within the line. All symbols should be defined and this can normally be done within the text, e.g. 'A bar of length l ...'. Tabulated lists should only be used in very complicated situations.

All maths variables should be in italic font, but functions like sin, tan, ln, etc., should be in a normal font. Subscripts and superscripts should be italicised if they represent a maths variable, but not if they only represent a label.

Describing apparatus

A labelled diagram is helpful, but shouldn't replace a textual description leading the reader through the essential features, for example: 'The specimen S is clamped between the copper electrodes P1 and P2'

For electrical systems a block diagram is normally sufficient. A circuit diagram should only be given if the design is part of the work being described, or if it is necessary for understanding the experiment.

Presenting results

The results should also be presented as continuous prose. Most results can be presented as tables or graphs that can be referred to in the text. Graphs are best for showing trends or giving a pictorial view of results, while tables are better where precise numerical values need to be given. Single values can be incorporated into the text.

Graphs count as figures and are referred to by their number in the same sequence as other figures (e.g. Figure 4). Tables are also referred to using numbers but in a separate sequence, i.e. you might have Figure 1, Figure 2, Table 1, Figure 3, etc. All quantities must have their units stated in their abbreviated form, e.g. µF for microFarads.

Writing discussions and conclusions

There can sometimes be confusion about the difference between the terms. A conclusion states what you as the author has finally decided, and it should match what is expected from the title and introduction. If you are measuring a physical quantity then your conclusion is its value.

A discussion enables you to write about the interpretation of your observations, the limitations of the method and suggestions for improvement.

A summary section is especially useful where the experiment has not lead to a straightforward conclusion. Summary and conclusion sections often work well as a numbered list.

Citing references

There are two main systems for citing references. The system you will use will depend on the style of the publisher. For example, the American Institute of Physics uses the number system while the major astrophysical journals use the Harvard system. Most undergraduate work uses the Harvard system.

In the Harvard system the author and year of publication are given in the text (e.g. 'Smith (1999) states ...') and then a list of references is given at the end in author surname order.

In the number system each reference is given a number in the text (e.g. [3]) and the references are listed by number at the end.

Using appendices

Generally, you should avoid having any appendices unless they are really needed. Their function is to allow a reader to follow the main text without getting bogged down in detail, e.g. for a piece of theory or computer code that the reader doesn't need to follow the main argument. Alternatively, they could describe a supplementary experiment such as a calibration.

If appendices are used then they must be referred to in the main text and any information derived from it should be quoted when used. A reader shouldn't have to turn to the appendix to follow the main text.