7.6 Lab Reports
Whether your research takes place in a university lab or on some remote work site, you will often have to write up the results of your work in a Lab Report. Most basically, this report will describe the original hypothesis your work attempts to test, the methodology you used to test it, your observations and results of your testing, your analysis and discussion of what this data means, and your conclusions.
In an academic context, especially in early courses, you are often asked to replicate the results of others rather than conduct your own original research. This is usually meant to instill an understanding of the scientific method into students, and teach students the proper use of instruments, techniques, processes, data analysis, and documentation. Once you demonstrate your ability to understand and apply the scientific method in these contexts, you will be able to go on to design your own research studies and develop new knowledge. Your reports then become the way you pass on this new knowledge to the field and to society at large.
For scientists and engineers to make valuable contributions to the sum of human knowledge, they must be able to convince readers that their findings are valid (can be replicated) and valuable. Thus, the way that you write these reports can impact the credibility and authority of your work; people will judge your work partly on how you present it. Yes, even lab reports have a persuasive edge and must make careful use of rhetorical strategies. Careless writing, poor organization, ineffective document design, and lack of attention to convention may cast doubt on your authority and expertise, and thus on the value of your work.
Science and Rhetoric
Some aspects of your report that might require you to think rhetorically are exemplified in how you approach the following questions:
- Why is this research important? How does it solve a problem or contribute in some way to expanding human knowledge?
- What have other researchers already discovered about this? How are you contributing to this conversation?
- What gaps are there in our knowledge about this topic?
- Why have you chosen this methodology to test your hypothesis? What limitations might it have?
- How and why do you derive these inferences from the data you have collected?
- What further research should be done? Why?
Writing a Lab Report
Your report will be based on the work you have done in the lab. Therefore, you must have a plan for keeping careful notes on what you have done, how you have done it, and what you observed. Researchers often keep a notebook with them in the lab, sometimes with pre-designed tables or charts for recording the data they know they will be observing (you might be given a lab manual to use while completing a particular experiment to record your observations and data in a pre-organized format). Try to plan ahead so that you can capture as much information as possible during your research; don’t try to rely only on memory to record these important details.
How you choose the content and format for your report will depend on your audience and purpose. Students must make sure to read lab manuals and instructions carefully to determine what is required; if writing for publication, make sure to follow the submission guidelines of the publication you are sending it to. Lab reports typically contain the elements outlined below.
Typical Elements of a Lab Report
Title: craft a descriptive and informative title that will enable readers to decide if this interests them, and will allow key words to be abstracted in indexing services. Ask your instructor about specific formatting requirements regarding title pages, etc.
Abstract: write a summary of your report that mirrors your report structure (Hypothesis, Methods, Results, Discussion, Conclusion) in condensed form—roughly one sentence per section. Ideally, sum up your important findings.
Introduction: establish the context and significance of your work, its relevance in the field, and the hypothesis or question your study addresses. Give a brief overview of your methodology for testing your hypothesis and why it is appropriate. If necessary for your readers, provide a specialized theoretical framework, background or technical knowledge to help them understand your focus and how it contributes to the field. Your instructor may describe a target audience for you; pay attention to that and write for that audience. More detailed reports may require a Literature Review section.
Materials and Methods: this section has two key purposes. First, it must allow any reader to perfectly replicate your method; therefore, you must provide a thorough description of what you used and how you conducted your experiment. Second, you must persuade your reader that your chosen methodology and the materials are appropriate and valid for testing your hypothesis, and will lead to credible and valid results. This section will generally include 1) a list of all materials needed (which may include sub-lists, diagrams, and other graphics), and 2) a detailed description of your procedure, presented chronologically. Traditionally, the Sciences have required writers to describe what they did using the Passive Voice, as passive mode emphasizes the materials and actions taken and de-emphasizes the role of the scientist in the process. This is slowly changing, as the use of Active Voice is more concise; however, you should consult your instructor about which is preferred in your context.
Results: this section presents the raw date that you generated in your experiment, and provides the evidence you will need to form conclusions about your hypothesis. Present only the data that is relevant to your results (but if you omit data, you may have to explain why it is not relevant). You can organize this section based on chronology (following your methodology) or on the importance of data in proving (or negating) the hypothesis (most important to least important). Present data visually whenever possible (in tables, graphs, flowcharts, etc.), and help readers understand the context of your data. Make sure you present the data honestly and ethically; do not distort or obscure data to make it better fit your hypothesis. If data is inconclusive or contradictory, be honest about that. In the Results section, you should avoid interpreting or explaining your data, as this belongs in your Discussion section.
Discussion: this section includes your analysis and interpretation of the data you presented in the Results section in terms of how well it supports your original hypothesis. Start with the most important findings. It is perfectly fine to acknowledge that the data you have generated is problematic or fails to support the hypothesis. This points the way for further research. If your findings are inconsistent, try to suggest possible reasons for this.
Conclusion: in 1-2 short paragraphs, review the overall purpose of your study and the hypothesis you tested; then summarize your key findings and the important implications. This is your opportunity to persuade the audience of the significance of your work.
Acknowledgements: formally express appreciation for any assistance you have received while preparing the report (financial/funding support, help from colleagues or your institution, etc.).
References: list all references you have cited in your report (such as those you may have included in a “literature review” in your introduction, or sources that help justify your methodology). Check with your instructor or publication guidelines for which citation style to use.
Appendices: any information that does not fit within the body sections, but still adds valuable information to your report, can be placed in an appendix. Where your Results section may present summarized data, the full data tables may appear in an appendix. You may also include logs, calculations, or notes on analytical methods. Be sure to refer to your appendices in the body of your report to signal where readers can find additional information.
How you write up the results of a scientific experiment will generally follow the formulaic pattern described above, but may vary depending on audience and purpose. As a student, you are often writing to demonstrate to your instructor that you have mastered the knowledge and skills required in a particular course. But remember that science writing generally focuses on the observable results, not on your “learning experience.” Your report should include what anyone doing this experiment might observe and conclude; these do not typically include personal reflections. In the professional academic world, your report may have to pass through a rigorous peer review process before being published in a scholarly journal. As a professional, your work may result in the development of products and services that will be used by the public, so documenting your process and findings has financial, safety, and legal implications. It is therefore critical that your writing is accurate and ethical.
A Note on Scientific Writing Style
Lab reports are often written using past tense, 3rd person, and passive verb constructions when describing what was done and what was observed. Why do you suppose that is?
Strict adherence to this style has in recent years been relaxed somewhat, and you might find more science writing that use first person and active rather than passive verb constructions. Can you think of reasons why this is changing?
For a fun example of Process Report that is similar in many ways to a lab report, see the attached Drafting Behind Big Rigs – Mythbusters Report [PDF]
When evaluating scientific literature that you read, you might find the the following TED-Ed video by David H. Schwartz helpful: Not all Scientific Studies are Created Equal.