Writing a Lab Report

The experiment

• It is vital that you understand the purpose of the experiment and keep notes and record all data accurately. Prepare a table in advance if necessary for inputting data.
• Consult lab manual and clarify instructions with lab supervisor if necessary. 

Preparing to write a draft

Consider the purpose of the report and consider your audience. Rather than writing the report for someone who knows about the experiment, imagine that you are writing to be published. This will ensure that you record every step in detail.

Structure

The structure of a scientific report is more or less fixed and conforms roughly to the following:

• Title
• Abstract
• Introduction
• Method
• Results
• Discussion
• Reference list
• Appendices

The report must be presented with the sections in this order, divide up with subsection numbers as follows:

• 1
• 1.1
• 1.2

The preliminary sections (i.e. Table of Contents) prior to the Introduction are not numbered. Appendices are usually labelled with letters, Appendix A, Appendix B, etc.

Latex is often used for typesetting as it can include numbering and cross-referencing, tables and figures, page layout and bibliography.

It may differ slightly depending on your department and you should consult your departmental handbook to follow exactly their instructions, but it will more or less follow the basic IMRAD structure: Introduction, Methods, Results and Discussion.

You don’t have to write the sections in this order. It may be best to write the abstract last and to begin with methods and results.

Following is a guideline on writing each section.

Title

Reflect the content of your paper in a concise manner which reflects your key findings. Be as straightforward and specific as your study was, for example, ‘The effect of temperature on the rate of solubility of sodium chloride.’ Abbreviations should be avoided.

Summary or abstract

The summary or abstract should be no more than 300 words. It should clearly state your. It should include an outline of the experimental approach, the main results (with relevant statistics) and conclusions, but no figures, tables or references.

Introduction

The introduction gives the purpose of the experiment/study. On the whole, short introductions are preferred. A long summary of the literature is not necessary and is better placed in the relevant sections of the Discussion. A clear statement of the problem and the immediate background as well as the aims of the experiment and its relevance should be given.

Method

This section details how you tested your hypothesis and clarifies why you performed your study in that particular way. It is not enough to design and carry out an experiment; it must be reproducible so that other researchers could carry out the experiment and get similar results. Therefore it is important that you record exactly what you did at every step of the experiment.

When procedures from a lab book or another report are followed exactly, simply cite the work and note that details can be found there.

Write about the experiment in chronological order of events in the past tense as you are reported something from the past, not primarily providing instructions for future use.

Describe the control.

Do not include your results in the Methods section.

Results

This is just raw data (i.e. with no analysis or discussion). It may be presented in text or visual form as you see fit. Do not repeat results in text and visual form.

• Text

A short paragraph that describes the results you obtained.

• Visual format

Decide on what visual format best suits your results for clarity, for example charts, tables, graphs, pie charts. You may need to label tables or charts to describe what data is recorded therein. Usually labels go above the data. If necessary, make sure you include the unit of measurement or time scale in the table where appropriate (for example, mm, cm, ml, seconds, minutes). If you have a number of visual representations of data which you will be referring back to in your Discussion section, you should label them, Figure 1, etc.

• A table or a chart?

A table is useful for capturing large amounts of exact data, while a visual representation in the form of one or more charts, graphs, maps, pie charts

is to render trends and developments which may be not be obvious from a table.

When using tables, line up your numbers aligned to the right. Don’t use a heavily lined grid, i.e., with vertical lines separating each column.

Table 1. Effect of Temperature on Rate of Solubility

Temperature of Solvent °C	Rate of Solubility g/sec
0	0
10	0
20	0
30	0
40	0
50	5.2
60	6.7
70	8.9
80	11.4

Figure 1 

When using graphs, plot the independent variable on the horizontal (x) axis and the dependent variable on the vertical (y) axis (independent variables are those whose values are controlled or selected by the person experimenting (experimenter) to determine its relationship to an observed phenomenon (the dependent variable).)

Graph 1. Effect of Temperature on Rate of Solubility

 

Number figures and tables separately and refer to them in the text by their number, i.e.

Figure 1 shows that the rate of solubility....

The rate of solubility increases from 40° (fig. 1).

Discussion

In the discussion section:

• interpret the data; do not restate the results
• judge the potential limitations of your experimental design and suggest potential modifications
• explore the implications of your findings, for example, what can you say from your findings about the rate of solubility generally.

Appendices

Give additional information that is too lengthy to include within your report. All data in the Appendix must have fully descriptive titles so that they can be understood without reference to the main text.

Proofreading and editing your final draft

You may find the following checklist helpful: 

• Have I included all sections required?
• Did I include all the relevant details and materials used in my Methods section?
• Did I include too much information?
• Have I included all relevant data?
• Is the data clear in my chosen format?
• Have I analyzed my results adequately?
• Have I acknowledged any weaknesses?
• Have I considered if there is a need to modify the experiment for the future?
• Have I run a Spell and Grammar check?
• Have I used the past tense and passive voice?