Mastering the Art of Writing a Lab Report: Step-by-Step Guide

While training to be a scientist, it is important to know how to write a traditional lab report and to be able to write effectively so that you can explain the details of your experiment clearly and explicitly.

You’ll be asked to prepare laboratory reports for several of your laboratory classes at the university.

Below are the guidelines for writing a scientific laboratory report. Additionally, laboratory reports are written in the past tense and the third person. And always remember that grammar and spelling are important.

Assignment to Write a laboratory report is common in science subjects and courses. Healthcare providers such as lab technologists also prepare lab test results.

People Also Read

• How to Write an Abstract for a Lab Report| Full Guide
• Learn How to Write a Research Proposal — A Complete Guide
• Methods for Separating Soluble Solutes in Investigations

These reports account for 25% of science courses.

That is a significant percentage, yet students do not pay enough attention when writing laboratory reports.

Another problem is laboratory reports do not have standard requirements. Different teachers have different expectations from their students’ laboratory reports.

The whole point of lab work is to report the lab test results or experiment findings and explain their importance.

All laboratory reports have key elements such as data, a list of materials, and a hypothesis.

After understanding all the essential elements you must include, you will only write a good laboratory report.

If you know the structure, you can write a laboratory report to match the requirements and expectations of your professor.

Requirements for Lab Reports

A laboratory report should:

• Present data from the experiment, such as the lab test results.
• Show your understanding of the concept behind the data.
• Explain in a brief statement the common reason why and how any variances happened and resulted in the expected or the unexpected results.
• Explain in a brief statement why the variances affected the experiment.
• Present your understanding of the concept the research was supposed to examine.

The point is it is not enough to understand the format of a laboratory report: You have to organize your ideas and thoughts carefully and coherently.

Structure of a lab report

The format you use for your laboratory report should consider your instructor’s instructions.

However, generally, a traditional lab report has the following sections. Ensure the entire lab report has the following sections of your lab report as well:

Title

• precisely identifies the focus of the lab

Abstract

• provides an overview of the report content, including findings and conclusions
• usually, the last part of the document is written
• may not be required in a short lab report

Introduction

• provides appropriate background to the experiment and briefly explains any relevant theories
• states the problem and hypothesis and
• concisely states the objective/s of the experiment

Method

• describes equipment, materials, and procedure(s) used, including mathematical equations
• may include flow charts of procedures and diagrams of the experimental set-up
• outlines any processing or calculations performed on the collected data (if applicable)

Results and Analysis

• presents the results of the experiment graphically or by using tables. Figures often include error bars where applicable
• discusses how results were analyzed, including error analysis

Discussion

• interprets key results about the aims/research question
• summarises key findings and limitations
• makes recommendations to overcome limitations and indicate future directions in research

Conclusion

• reminds the reader what problem is being investigated
• summarises the findings of the problem/hypothesis
• briefly identifies big-picture implications of the findings (Answers the question “So What?”)

References

• lists the publication details of all sources cited in the text, allowing readers to locate sources quickly and easily
• usually follows a specific referencing style

Appendices

• An appendix (plural = appendices) contains material too detailed to include in the main report, such as raw data tables or detailed calculations.

Title

The title tells the reader the focus of the experiment.

The title briefly tells the reader what the experiment is about and what the report includes.

It may or may not indicate the conclusion.

The following is an example of a good lab report title:

An experiment to determine the chemical equilibrium using Le Chatellier’s Principle.

In your title, be precise (avoid wordiness), and do not use abbreviations.

The title normally appears on the title page.

But, some instructors will tell you not to include a title page.

If the page is a requirement, it should be a single page with the following information:

• The name (title) of the experiment.
• Your name and the name of other students you experimented with.
• The instructor’s name.
• The date.

Of course, the title page structure might be determined by the academic paper format specified.

However, do not include the page if it is not in the instructions.

Abstract

An abstract is a summary of the report.

The length of the abstract should be 10% of the whole report.

Therefore, a 500-word lab report should have an abstract of about 50 words.

Still, an abstract should not exceed 250 words or one page.

The abstract should contain important things such as the results, your interpretation, and a brief explanation of the methods.

From the abstract, your reader should tell what the report is about and if it is relevant to their research.

The abstract should be just one paragraph; therefore, it should not be detailed or contain too many technical terms.

In simpler terms, an abstract is the short version of your lab report.

Introduction

The introduction of a lab report informs the reader of the relevance of the experiment.

Therefore, the first thing you do in your introduction is background information about the experiment.

You are providing this background information so the reader can understand the hypothesis.

Sometimes this section may contain background information, briefly summarize how the experiment was performed, state the experiment’s findings, and list the investigation’s conclusions. Even if you don’t write a whole introductory section, you need to state the purpose of the experiment or why you did it. This would be where you state your hypothesis.

A hypothesis is an answer your experiment offers.

An example of a hypothesis is: Temperature affects the rate of diffusion.

To create a hypothesis easier, ask yourself how the theory you are trying to prove connects to your experiment.

Also, in the introduction, show how your experiment solves real-world problems.

As much as you should include all relevant background information, do not get carried away and state the experiment results, materials, and methods used.

Materials and methods

In this section, list the materials used in your lab notebook.

Then, outline the methods used to gather the data clearly and chronologically.

The idea is to help the reader understand how the experiment was conducted.

However, do not provide a step-by-step experiment process; that information is included in the lab manual.

Include information about any special apparatus or techniques used in the experiment.

Do not be too detailed or copy the experiment procedure from the lab manual.

During the lab, take detailed notes in your lab notebook on procedures and results and note any differences in procedures or expected outcomes. Record enough detail to allow someone else to repeat the experiment based on your notes.

Lab handout example

Week 5 Laboratory instructions

Procedure

1. Use a clean pipette to measure 25ml of HCl(aq) into the conical flask.
2. Rinse a burette with standardized NaOH(aq).
3. Fill the burette to the 0.0ml marking with standardized NaOH(aq). Remember to read from the center of the meniscus and eye level. Record the actual reading in Table 1.
4. Place a sheet of white paper under the burette. This makes it easier to observe the color change during the reaction.
5. Place the conical flask onto the white paper…

Lab report example

Procedure

The equipment was arranged as shown in Fig. 2.

25.0ml HCl(aq) was pipetted into a 100ml conical flask. A burette was clamped to a retort stand and filled with standardized NaOH(aq), and you recorded the initial measurement. The conical flask was placed on top of a piece of white paper below the burette. Five drops of universal indicator solution were added to the flask…

Tip: Thoughts on the passive voice in laboratory reports procedure

You should write your lab reports in the active voice or present tense. Passive voice is better for important official documents because it makes them sound more impersonal and neutral.

Instead of saying, “The x was measured by the student,” say, “I measured the x.“

Instead of saying, “They was calculated by the student,” say, “I calculated the y.” This is just normal English.

Using passive voice when describing experiments you did yourself is a little awkward writing. If you’re going to do something, it’s probably worth getting credit for it.

Results

Under the results section, summarize your data.

Your results should appear in a logical and chronological order.

You can present your data in tables and graphs.

The important thing is to label everything correctly and clearly, indicating all the measuring units.

There are two different kinds of data you should record; quantitative and qualitative.

Quantitative data is observable and measurable in units such as grams, millimeters, and degrees.

On the other hand, qualitative data is unmeasurable observable data.

It includes things you observe with your senses, such as smell and color.

Do not discuss if the results were what you expected or compare your results with those of other researchers.

Titles and captions

• Tables should be labeled numerically as Table 1, Table 2, etc. Table captions appear above the table.
• Everything else (graphs, images, diagrams, etc.) is labeled numerically as Figure 1, Figure 2,  etc. (References to figures in the main body of the text are usually written in abbreviated form, e.g., ‘see Fig. 1’). Figure captions appear below the figure.
• Data can be presented in other formats, such as images:

Discussion

The discussion is an essential section of the laboratory report as it demonstrates your ability to interpret the data and results of the experiment.

It would help if you discussed whether or not the results support your hypothesis.

In this section, you also compare your work to those of other scientists: Were your results consistent with those of other scientists?

However, do not discuss human errors.

Therefore, do not report that you accidentally used the wrong chemical at some point in your experiment.

References

When providing background information in your introduction or supporting your results in the discussion, you may have to cite the works of other scientists or refer to your lab manual.

You should properly cite all external sources, and you will include these citations under the references section.

The academic referencing style specified will determine the format of the citations.

Most instructors prefer APA and CSE for laboratory reports.

However, do not assume; confirm with your professor the formatting style required.

If your research was based on someone else’s work or cited facts that require documentation, you should list these references.

Conclusion

In conclusion, write what you learned from the experiment.

Discuss the lesson learned regardless of whether the results supported your hypothesis.

The point is to demonstrate to the reader that the experiment was successful.

So, instead of summarizing the results, explain the meaning.

Appendices

An appendix is an information that does not have to be included in the laboratory report but could help a reader who wants to learn more about the experiment or the theory the experiment attempted to prove.

The use of appendices helps to unclutter the laboratory report.

Note that if you include appendices, you should refer to them in the laboratory report.

Things that you can include in the appendices section include:

• Photographs of the experiment may help the reader better understand the findings.
• Calculations that provide a better understanding of the methodology section.
• The raw data from the lab
• Data tables that are not crucial to the discussion in the lab of the results but may be helpful to the reader as a reference

Each unique item should be a separate appendix.

Additional tips on how to write a laboratory report

• Proofread your paper at least two times. When proofreading, check the flow of the content and confirm you have followed all the instructions.
• Check that there is no plagiarism. Plagiarism is more than copying material word for word; it also uses someone else ‘s ideas or phraseology without referencing another work or another person.
• Use the past tense when discussing methodology and findings.

Conclusion

A lab report provides useful information about an experiment.

It is an important assignment that contributes a significant percentage to your grade.

All you have to do to write a laboratory report excellently is follow the format and tips discussed above and the instructions from your teacher.

FAQs

Jamie Boone

Experienced writer and dedicated professor with a passion for crafting compelling narratives and nurturing the next generation of critical thinkers