Lab reports

How to structure and communicate your findings in a lab report.

Purpose of a lab report

  • To describe an experiment you’ve carried out in the lab
  • To communicate the results.

Writing lab reports is part of learning to be a scientist and provides you with experience in writing in a scientific style.

Lab report structure

Different departments might have different requirements, so always check with your lecturer to find out the exact requirements for your lab report. Reports that communicate the results of an experiment generally follow a format known as IMRAD: Introduction, Method, Results, (And) Discussion. Each section has a specific purpose and contains different information.

  • Introduction

    The introduction provides an overview of the experiment and informs the reader about what to expect in the report. It should include:

    • information that puts the experiment into context
      • What have you investigated?
      • Why is it worth investigating? (significance/rationale)
      • How does your work connect to previous studies? (e.g. Are you replicating a study? Are you building on previous research?)
    • the aims of the experiment
    • the hypothesis/hypotheses (may be in your laboratory manual)
  • Method

    In this section you explain to the reader how you carried out the experiment. It should be written in the past tense and include enough detail to enable a reader to replicate the experiment. This means that you need to be specific (e.g. detail the concentration of the solution used, the duration of the experiment, the temperature of the oven).

    Include:

    • the materials, subjects and equipment (e.g. chemicals, experimental animals, apparatus) you used
    • the steps you took (in chronological order) in carrying out the experiment.
    • any assumptions you made that might have influenced your methods.
  • Results

    This is a very important section of your lab report because it’s where you present your findings. You need to present all relevant findings in a clear, concise, and accurate way that is easy for the reader to follow and understand. Never falsify your findings, even if they don’t support the hypothesis.

    You might find it useful to present some of your findings using tables or figures. A figure can be a graph, diagram, drawing, photo or map. Sometimes your lecturer will advise you which to use, but if you have to make this decision yourself, think about the most effective way to present your findings in a clear visual form. For example:

    • Tables are useful for presenting summarised data in rows and columns
    • Pie charts are useful for communicating findings expressed as different percentages of a whole
    • Graphs are useful for demonstrating numerical difference or trends.

    Any tables and figures you use should enhance the information you present in the text of the report. Make sure you write about the key findings and evidence that emerge from the tables and figures rather than merely repeating their details.

    Always refer to a table or figure in the text of your report. For example: ‘As shown in Figure 1, almost all of the energy consumed (95%) was produced using non-renewable sources.'

  • Discussion

    In this section, you analyse your findings within the context of the information you’ve presented in your introduction. Your discussion might include:

    • whether your findings support the hypothesis. How do you explain any discrepancy?
    • the extent to which your findings agree with previous studies in the area. How do you explain any disagreement?
    • Was there anything you could have done differently in your methods?

    The discussion should end with a concluding paragraph that states the significance of your findings. Also indicate the possible direction of further research and discuss how the methodology could be improved for future studies.

  • Other sections
    • References: Include at the end of your report a list of all the references you’ve cited in the report (e.g. textbooks, articles, lab manuals, websites). Check with your lecturer what referencing style you need to use.
    • Appendices (following the references): for detailed information or raw data you want to include. Appendices should be numbered (e.g. Appendix 1, Appendix 2) and have a clear heading. When referring to information in an appendix, you need to indicate where this can be found. E.g. ‘Detailed figures can be found in Appendix 1’.
    • Abstract (if required): Sits at the very beginning of a report (before the introduction) and briefly summarises the whole report. The abstract should include: the rationale and aims of the experiment, an overview of the method, the main findings and your conclusions. The abstract can be written last when you know exactly what your findings and conclusions are.

Writing style in lab reports

Clear

Use short simple sentences rather than long complicated ones. Although you will need to use specialist terms in your report, you should also use familiar non-technical terms where possible. Avoid vague qualifying words such as rather, really and quite.

Objective

Scientific writing should be unbiased. You should present facts and evidence for your argument. Avoid using emotive language.

Accurate

Avoid ambiguous statements such as ‘The volume increased slightly in the first experiment, but a lot more in the second.’ You could quantify these increases to make the sentence more accurate.

If you are making comparisons, be consistent in your use of units of measurement. Statements such as ‘The volume increased by one quarter in the first experiment but decreased by 12% in the second’ can be difficult for the reader to follow.

Brief

Every word you write in your lab report counts, so don’t waste words repeating ideas or using unnecessarily complicated expressions. For example, rather than writing not unlikely, use likely, and rather than writing exact duplicate, use duplicate or copy.

Final tips

Lab reports provide great opportunities to communicate your experiment results and what they mean. Make sure you analyse and interpret your results rather than merely describing them. Also remember that the reader of your lab report expects clear, objective, accurate and brief writing.

Two people looking over study materials

Looking for one-on-one advice?

Get tailored advice from an Academic Skills Adviser by booking an Individual appointment, or get quick feedback from one of our Academic Writing Mentors via email through our Writing advice service.

Go to Student appointments