How to Write a Lab Report – with Example/Template

Perhaps you’re in the midst of your challenging AP chemistry class in high school, or perhaps college you’re enrolled in biology, chemistry, or physics at university. At some point, you will likely be asked to write a lab report. Sometimes, your teacher or professor will give you specific instructions for how to format and write your lab report, and if so, use that. In case you’re left to your own devices, here are some guidelines you might find useful. Continue reading for the main elements of a lab report, followed by a detailed description of the more writing-heavy parts (with a lab report example/lab report template). Lastly, we’ve included an outline that can help get you started.

What is a lab report?

A lab report is an overview of your experiment. Essentially, it explains what you did in the experiment and how it went. Most lab reports end up being 5-10 pages long (graphs or other images included), though the length depends on the experiment. Here are some brief explanations of the essential parts of a lab report:

Title: The title says, in the most straightforward way possible, what you did in the experiment. Often, the title looks something like, “Effects of ____ on _____.” Sometimes, a lab report also requires a title page, which includes your name (and the names of any lab partners), your instructor’s name, and the date of the experiment.

Abstract: This is a short description of key findings of the experiment so that a potential reader could get an idea of the experiment before even beginning.

Introduction: This is comprised of one or several paragraphs summarizing the purpose of the lab. The introduction usually includes the hypothesis, as well as some background information.

Lab Report Example (Continued)

Materials: Perhaps the simplest part of your lab report, this is where you list everything needed for the completion of your experiment.

Methods: This is where you describe your experimental procedure. The section provides necessary information for someone who would want to replicate your study. In paragraph form, write out your methods in chronological order, though avoid excessive detail.

Data: Here, you should document what happened in the experiment, step-by-step. This section often includes graphs and tables with data, as well as descriptions of patterns and trends. You do not need to interpret all of the data in this section, but you can describe trends or patterns, and state which findings are interesting and/or significant.

Discussion of results: This is the overview of your findings from the experiment, with an explanation of how they pertain to your hypothesis, as well as any anomalies or errors.

Conclusion: Your conclusion will sum up the results of your experiment, as well as their significance. Sometimes, conclusions also suggest future studies.

Sources: Often in APA style, you should list all texts that helped you with your experiment. Make sure to include course readings, outside sources, and other experiments that you may have used to design your own.

How to write the abstract

The abstract is the experiment stated “in a nutshell”: the procedure, results, and a few key words. The purpose of the academic abstract is to help a potential reader get an idea of the experiment so they can decide whether to read the full paper. So, make sure your abstract is as clear and direct as possible, and under 200 words (though word count varies).

When writing an abstract for a scientific lab report, we recommend covering the following points:

• Background: Why was this experiment conducted?
• Objectives: What problem is being addressed by this experiment?
• Methods: How was the study designed and conducted?
• Results: What results were found and what do they mean?
• Conclusion: Were the results expected? Is this problem better understood now than before? If so, how?

How to write the introduction

The introduction is another summary, of sorts, so it could be easy to confuse the introduction with the abstract. While the abstract tends to be around 200 words summarizing the entire study, the introduction can be longer if necessary, covering background information on the study, what you aim to accomplish, and your hypothesis. Unlike the abstract (or the conclusion), the introduction does not need to state the results of the experiment.

Here is a possible order with which you can organize your lab report introduction:

• Intro of the intro: Plainly state what your study is doing.
• Background: Provide a brief overview of the topic being studied. This could include key terms and definitions. This should not be an extensive literature review, but rather, a window into the most relevant topics a reader would need to understand in order to understand your research.
• Importance: Now, what are the gaps in existing research? Given the background you just provided, what questions do you still have that led you to conduct this experiment? Are you clarifying conflicting results? Are you undertaking a new area of research altogether?

Lab Report Example (Continued)

• Hypothesis: Now, state your hypothesis. It’s important to note that a hypothesis is not the same as predicting a future outcome of an experiment. Rather, it’s a statement of explanation for observations, which should be written in present tense and as specifically as possible (for more information on hypotheses, consider reading this article from the National Library of Medicine). Here’s an example of a prediction vs. a hypothesis:
  • Prediction: The plants placed by the window will grow faster than plants placed in the dark corner.
  • Hypothesis: Basil plants placed in direct sunlight for 2 hours per day grow at a higher rate than basil plants placed in direct sunlight for 30 minutes per day.
• How you test your hypothesis: This is an opportunity to briefly state how you go about your experiment, but this is not the time to get into specific details about your methods (save this for your results section). Keep this part down to one sentence, and voila! You have your introduction.

How to write a discussion section

Here, we’re skipping ahead to the next writing-heavy section, which will directly follow the numeric data of your experiment. The discussion includes any calculations and interpretations based on this data. In other words, it says, “Now that we have the data, why should we care?”  This section asks, how does this data sit in relation to the hypothesis? Does it prove your hypothesis or disprove it? The discussion is also a good place to mention any mistakes that were made during the experiment, and ways you would improve the experiment if you were to repeat it. Like the other written sections, it should be as concise as possible.

Here is a list of points to cover in your lab report discussion:

• Support or reject the hypothesis: Begin by stating whether or not the results of this experiment supported your hypothesis. You may also briefly summarize your results in this section, though avoid going into great detail. Note: this is not a statement of proof, just your findings in relation to the hypothesis.
  • Weaker statement: These findings prove that basil plants grow more quickly in the sunlight.
  • Stronger statement: These findings support the hypothesis that basil plants placed in direct sunlight grow at a higher rate than basil plants given less direct sunlight.

Lab Report Example (Continued)

• Factors influencing results: This is also an opportunity to mention any anomalies, errors, or inconsistencies in your data. Perhaps when you tested the first round of basil plants, the days were sunnier than the others. Perhaps one of the basil pots broke mid-experiment so it needed to be replanted, which affected your results. If you were to repeat the study, how would you change it so that the results were more consistent?
• Implications: How do your results contribute to existing research? Here, refer back to the gaps in research that you mentioned in your introduction. Do these results fill these gaps as you hoped?
• Questions for future research: Based on this, how might your results contribute to future research? What are the next steps, or the next experiments on this topic? Make sure this does not become too broad—keep it to the scope of this project.

How to write a lab report conclusion

This is your opportunity to briefly remind the reader of your findings and finish strong. Your conclusion should be especially concise (avoid going into detail on findings or introducing new information).

Here are elements to include as you write your conclusion, in about 1-2 sentences each:

• Restate your goals: What was the main question of your experiment? Refer back to your introduction—similar language is okay.
• Restate your methods: In a sentence or so, how did you go about your experiment?
• Key findings: Briefly summarize your main results, but avoid going into detail.
• Limitations: What about your experiment was less-than-ideal, and how could you improve upon the experiment in future studies?
• Significance and future research: Why is your research important? What are the logical next-steps for studying this topic?

Template for beginning your lab report

Here is a compiled outline from the bullet points in these sections above, with some examples based on the (overly-simplistic) basil growth experiment. Hopefully this will be useful as you begin your lab report.

1) Title (ex: Effects of Sunlight on Basil Plant Growth)

2) Abstract (approx. 200 words)

1. 1. Background (This experiment looks at…)
   2. Objectives (It aims to contribute to research on…)
   3. Methods (It does so through a process of….)
   4. Results (Findings supported the hypothesis that…)
   5. Conclusion (These results contribute to a wider understanding about…)

Lab Report Example (Continued)

3) Introduction (approx. 1-2 paragraphs)

1. 1. Intro (This experiment looks at…)
   2. Background (Past studies on basil plant growth and sunlight have found…)
   3. Importance (This experiment will contribute to these past studies by…)
   4. Hypothesis (Basil plants placed in direct sunlight for 2 hours per day grow at a higher rate than basil plants placed in direct sunlight for 30 minutes per day.)
   5. How you will test your hypothesis (This hypothesis will be tested by a process of…)

4) Materials (list form) (ex: pots, soil, seeds, tables/stands, water, light source)

5) Methods (approx. 1-2 paragraphs) (ex: 10 basil plants were measured throughout a span of…)

6) Data (brief description and figures) (ex: These charts demonstrate a pattern that the basil plants placed in direct sunlight…)

7) Discussion (approx. 2-3 paragraphs)

1. 1. Support or reject hypothesis (These findings support the hypothesis that basil plants placed in direct sunlight grow at a higher rate than basil plants given less direct sunlight.)
   2. Factors that influenced your results (Outside factors that could have altered the results include…)
   3. Implications (These results contribute to current research on basil plant growth and sunlight because…)
   4. Questions for further research (Next steps for this research could include…)

Lab Report Example (Continued)

1. Conclusion (approx. 1 paragraph)
   1. Restate your goals (In summary, the goal of this experiment was to measure…)
   2. Restate your methods (This hypothesis was tested by…)
   3. Key findings (The findings supported the hypothesis because…)
   4. Limitations (Although, certain elements were overlooked, including…)
   5. Significance and future research (This experiment presents possibilities of future research contributions, such as…)
2. Sources (approx. 1 page, usually in APA style)

Final thoughts – Lab Report Example

Hopefully, these descriptions have helped as you write your next lab report. Remember that different instructors may have different preferences for structure and format, so make sure to double-check when you receive your assignment. All in all, make sure to keep your scientific lab report concise, focused, honest, and organized. Good luck!

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