What is a lab report?

The main purpose of a lab report is to summarize scientific research you've performed and explain how the results relate to your hypothesis. Technical reports like these are an important part of science because, as a scientist, you have a responsibility to communicate your findings, what you learned, and why it matters.

Your report should demonstrate that you understand:

• Basic information and existing knowledge related to your topic & hypothesis
• Procedures, materials, and conditions used in the experiment
• Data that was collected during the experiment and how to interpret it
• How to illustrate your data using appropriate graphs, tables, or figures
• The statistical methods that were used (and why)
• What happened, why it happened, and what it signifies in relation to your hypothesis

GOOD lab reports

To write the perfect lab report, you need to think about who you're writing for and what they want to know. I recommend writing as if your reader has the same level of experience as you, i.e., a student taking the same course but in a different lab section. The look of your lab report may vary based on your research topic, but you should always aim to:

• Communicate the findings from your work and help your reader understand them.
• Write your procedures with enough detail that your experiment and results could be reproduced later.
• Write each section of the report with enough detail that your purpose, hypothesis, and rationale are well-understood.
• Tell your reader a logical story about what was done, what the results were, and your interpretation of the findings.
• Convey essential information as concisely and effectively as possible.

BAD lab reports

In my experience, bad lab reports are often written last minute and lack a general understanding of the experiment. I recommend starting on your report early enough to ask a friend or two to review it for you. If your friends don't understand what your report is about, it's safe to assume the person grading your report won't either.

The best lab reports have clear, coherent story lines and a natural flow. It should be easy for your reader to understand the purpose of your experiment, findings, and the significance of your work.

Grammar is another area where I've seen students struggle. You want to be sure that you're using terminology that flows with your style of writing and that you are confident using on paper AND in a conversation. The way I expand my scientific vocabulary is simple — I stop every time I encounter a word I don't know and Google, YouTube, and PubMed search it until I understand.

[ If you're looking for additional writing help, leave your questions in the comments below so I can answer them in an upcoming post! ]

The structure of a lab report

Writing a lab report can be intimidating, but whether you're a student or Nobel Prize winner, the secret to a great piece of scientific writing is its organization.

I like to think of the report and each of its sections as an extension of the scientific method:

As a whole, a lab report communicates scientific results. The introduction includes background research & states the hypothesis. Materials & methods show how the hypothesis was tested. The results section provides the data. And lastly, the discussion gives a detailed analysis of the data, states if the results support the hypothesis, and sometimes leaves the reader with a new question to investigate!

In general, lab reports require these sections: 

Title

The title should be brief and describe the main point of the experiment. Even better if you can come up with a catchy one — scientists love a good pun!

If your instructor asks for a title page, this is usually a cover page that states: the title of your report, your name/lab partners, instructor's name, class section, and date.

Abstract

The abstract should be a brief (one paragraph) overview of what is in the report. It should summarize the purpose of the experiment, your hypothesis, methods, key findings, significance, and conclusions. The goal is to get your reader interested in the work enough to keep reading!

This section can be challenging to write, and is best saved for last.

Introduction

The introduction should state: the purpose of the experiment, relevant background/previous research on the subject, the hypothesis, and the reasons you believe the hypothesis is feasible. Include in-text citations as appropriate.

Details about the experiment should be written in past tense, since it has already been finished. Theory, however, should be written in present tense. Always write this part in your own words, rather than quoting or paraphrasing references.

This section should set the scene for what's to follow.

Materials & Methods

In the materials and methods, you want to describe the procedures used to test your hypothesis in detail. Describe what you did, in the order you did it. Never use bullet points or numbered steps! You should be detailed enough that someone could reproduce your experiment and obtain similar results using what you've written.

In the past, scientists avoided writing in the first person (I or we) because who performed the experiment is usually not important to the procedure. However many style guides now recommend using the active voice, so you'll want to check in with your instructor. You can write that you recorded results, or how you recorded them, but you shouldn't write about what your results were just yet. Remember that you're describing what already happened, so you should again write in the past tense.

This section is merely detailing how you tested your hypothesis.

Results

The results section is where you present the data you collected in the experiment and describe trends you observed. You can write this part in the past tense because the experiment has already happened.

Results is usually a short section because at this point you're just reporting facts, not interpreting your data or drawing conclusions just yet!

Data should be organized into tables, figures, and diagrams. Use as many visual aids as you need to clearly show how your hypothesis was or wasn't supported. Each should be appropriately labeled and clearly state what is being shown. 

• Tables should be labeled as Table 1, Table 2, etc. and have the title above the table.
• Figures (graphs, diagrams, etc.) should be labeled as Figure 1, Figure 2, etc. and have their title below the figure.

Remember to keep it professional — never use images you found on the web or have taken with your cell phone unless you've been asked to do so by your instructor.

This section should include all of your tables/figures and explicitly state all significant results in verbal form. 

Discussion

The discussion section is where you explain, analyze, and interpret your findings in detail. 

• Draw conclusions based on your findings
• Explain whether your results supported your hypothesis
• Acknowledge weaknesses in the experiment & suggest improvements
• Explain unexpected results
• Relate your findings to existing knowledge (include in-text citations)
• Convey the significance of your experiment

This section focuses on the significance of your results, weaknesses in the experiment, and what you have learned. 

References

The references section consists of an alphabetical or numerical list of the resources you used in writing your report. All full citations on your References list should match to an in-text citation.

Include your lab manual and any external research you have done. Formatting can vary based on the field of research and personal preference, so ask your instructor what is expected of you. All references and in-text citations should be formatted consistently throughout the report.

This section should be constructed as in-text citations are added to your report.

...and that's it, your perfect lab report is done!