The Lab Report

Lab reports are a key part of STEM (Science, Technology, Engineering, and Mathematics) courses, yet little focus is given to teaching how to write them effectively. This document provides a general framework for lab reports that you can modify as needed. Regardless of these variations, the main purpose of a lab report is the same: to present your findings and explain their importance. With this in mind, we’ll go over the report format and its key components.

A strong lab report goes beyond simply presenting data; it showcases the writer’s understanding of the concepts that underpin the data. It’s not enough to just report the expected and observed results—you must also analyze any discrepancies, explaining how and why they occurred, how they influenced the experiment, and how they relate to the underlying principles being tested. While a clear format can guide your writing, it cannot substitute for clear thinking and well-organized expression. It’s essential to carefully structure your ideas and present them in a logical, coherent manner.

Scoring Rubric: Writing Quality (10 points)

Title is evaluated for clarity and purpose in original words.

• Excellent (8 points): The report is well-written with proper grammar, punctuation, and scientific tone. 
• Good (6 points): The report is mostly well-written with minimal grammatical errors or awkward phrasing.
• Satisfactory (4 points): The report contains some grammatical errors or awkward phrasing, but it does not significantly affect comprehension.
• Needs Improvement (2 points): The report contains numerous grammatical errors, making it difficult to follow.

CHE 4 Lab Report Structure

The structure of a lab report can vary depending on the scientific field and course requirements, but it generally includes the purpose, methods, and results of the experiment. Each section of a lab report serves a distinct function. While these sections are common to most lab reports, some may be omitted or combined depending on the requirements. For instance, some reports may integrate research aims into the introduction, and a separate conclusion may not always be necessary.

1: Title Page

Title Page clearly reflects the focus of your study and should include the name of the experiment, the names of all lab partners, and the date. Titles should be clear, informative, and concise, typically under ten words. Craft a title that accurately reflects the central focus or goal of your study. While creativity is not necessary, the title should clearly convey the topic in a way that helps the reader immediately understand the purpose of the experiment or research. For example, instead of "Lab #2," use a more descriptive title like "Lab #2: Using Colligative properties to Solve the Problem". Take a look a professional published titles for your Instructor on Google Scholar.

Scoring Rubric: Title (4 points)

Title is evaluated for clarity and purpose in original words.

• Excellent (4 points): The title is clear, easy to understand, and directly communicates the focus of the experiment. 
• Good (3 points): The title is mostly clear, but some wording could be improved for clarity. 
• Satisfactory (2 points): The title is somewhat clear, but may use vague or overly complex language.
• Needs Improvement (1 points): The title is unclear, confusing, or misleading.
• Missing (0): No title written

2: Abstract

The abstract provides a concise summary of your research goals, methods, results, and conclusions. An abstract provides a concise summary of a lab report, typically ranging from 150–300 words. It should briefly outline the research objectives, methods and materials used, key results, and the final conclusion. Think of the abstract as a snapshot of your full report, giving readers a quick preview of your work. Write it last, in the past tense, after completing the other sections, so you can effectively summarize each part. consider these guiding questions to craft an effective lab report abstract:

• What is the broader context of your study?
• What research question were you addressing?
• How did you conduct the experiment?
• What did your results reveal?
• How did you interpret the results?
• Why are your findings important?

Scoring Rubric: Abstract (12 points)

The abstracts in lab reports are assess based on clarity, conciseness, and completeness.

• Excellent (12 points): Abstract is clear, concise, and well-organized; no unnecessary details. Stays within 150-300 words.
• Good (9 points): Abstract is clear and concise but may contain some unnecessary details. Stays within 150-300 words.
• Satisfactory (6 points): Abstract is somewhat clear but includes some irrelevant information or is slightly too long/short.
• Needs Improvement (3 points): Abstract is unclear or overly wordy. Missing focus or deviates from the required word count.
• Missing (0 points): No abstract written or extremely haphazardly prepared

3: Introduction

The Introduction of your lab report should set the stage for your experiment. Your introduction does not have to be lengthy, but it must be a solid paragraph (or rmore). A useful structure for writing it is the funnel approach:

1. Begin with a broad overview of the general research area.
2. Narrow the focus down to your specific study.
3. Conclude with a precise research question.

Start by providing background information on the topic and explaining its relevance in either a practical or theoretical context. Summarize key prior research, and clarify how your study aims to confirm, extend, or fill any gaps in existing knowledge.

Next, delve into the theoretical foundation of your study, outlining any relevant laws or equations that will be used. Clearly state your primary research objectives and expectations by presenting your hypotheses.

Scoring Rubric: Introduction (12 points)

The introduction is evaluations on clarity, relevance, and logical flow in introducing the study.

• Excellent (12 points): Provides comprehensive background that fully explains the context of the experiment.
• Good (9 points): Relevant theories, concepts, and previous research are thoroughly covered. 
• Satisfactory (6 points): Background is clear and provides adequate context, though it may miss some relevant details or references.
• Needs Improvement (3 points): Background is somewhat clear but lacks key details or sufficient explanation of context. 
• Missing (0 points): The section is missing or extremely haphazardly prepared

4: Experiment 

The Experiment section of a lab report is where you detail every aspect of your experiment, including the materials used, equipment, and the step-by-step procedure you followed, providing enough information so that another researcher could replicate your experiment exactly. Use clear paragraph structure to describe each step as it was actually carried out, not how it was intended to occur. Make sure to note any deviations from the procedure outlines in the laboratory (e.g., "At step 2, only performed two repetitions were collected instead of three due to time"). Ideally, any researcher should be able to replicate your experiment based on your description alone. Think that you are rewriting the lab manual.

Scoring Rubric: Method and Materials (8 points)

Paragraph form description of procedure written in own words. Could be given to another student and they could perform the lab off this alone. Not allowed to use bullet points.

• Excellent (8 points): The procedure is described in clear, concise language, with all steps outlined in a logical, easy-to-follow sequence.
• Good (6 points): The procedure is mostly clear and well-structured but may include minor ambiguities or missing details.
• Satisfactory (4 points): The procedure is somewhat clear but lacks important details or has minor organizational issues.
• Needs Improvement (2 points): The procedure is unclear, disorganized, or missing key steps.
• Missing (0 points): The section is missing or extremely haphazardly prepared

Relevant equations are given and numbered. A sample calculation is given for each calculated value, calculated values below.

• Excellent (8 points): Provides a succinct but thorough description of the methods and materials used.
• Good (6 points): Describes methods adequately, but some details may be unclear or missing.
• Satisfactory (4 points): Methods are mentioned, but lack important details or clarity.
• Needs Improvement (2 points): Methods are poorly described or missing key information.
• Missing (0 points): The section is missing or extremely haphazardly prepared

5: Results

The Results section presents the statistical analyses of the collected data. In this section, you should clearly explain how the results from these tests either support or contradict your initial hypotheses (if applicable). The key results to include are:

• Descriptive statistics (simple summaries about the sample and about the observations that have been made. Such summaries may be either quantitative, i.e. summary statistics, or visual, i.e. simple-to-understand graphs.)
• Results from statistical tests (if applicable)
• The significance of the test outcomes (if applicable)
• Estimates of standard error or confidence intervals

Scoring Rubric: Results (16 points)

(4 points): All relevant lab data are shown and tabulated. Observations are recorded. Numbers have units and tables are correctly formatted. Discussed significance of each figure and table. Discussed sources of error and how to minimize them. Third person past-tense. Referenced each figure or table.

• Excellent (4 points): Data is presented clearly and logically, using appropriate tables, graphs, and figures. All are well-labeled, easy to interpret, and relevant to the findings.
• Good (3 points): Data presentation is clear, with appropriate tables, graphs, and figures. Some minor improvements in labeling or clarity may be needed.
• Satisfactory (2 points): Data presentation is adequate but could benefit from clearer organization, labeling, or inclusion of more visual aids.
• Needs Improvement (1 points): Data presentation is unclear, disorganized, or lacking necessary visual aids (e.g., graphs or tables).
• Missing (0 points): The section is missing or extremely haphazardly prepared

(4 points): All relevant lab data are and accurate.

• Excellent (4 points): All data is accurate and matches the recorded observations. No inconsistencies or errors are present.
• Good (3 points): Data is mostly accurate, but there may be a minor discrepancy or error in one or two recorded observations.
• Satisfactory (2 points): Some data is inaccurate or there are inconsistencies in the reported results.
• Needs Improvement (1 points): Data contains significant inaccuracies or discrepancies.
• Missing (0 points): The section is missing or extremely haphazardly prepared.

(4 points): Relevant equations are given and numbered. A sample calculation is given for each calculated value.

• Excellent (4 points): The procedure is described in clear, concise language, with all steps outlined in a logical, easy-to-follow sequence.
• Good (3 points): The procedure is mostly clear and well-structured but may include minor ambiguities or missing details.
• Satisfactory (2 points): The procedure is somewhat clear but lacks important details or has minor organizational issues.
• Needs Improvement (1 points): The procedure is unclear, disorganized, or missing key steps.
• Missing (0 points): The section is missing or extremely haphazardly prepared

(4 points): All values and figures required from the lab manual are correctly calculated and tabulated. Correct units and table formatting. Compared to a reference value when possible. Error analysis if applicable.

• Excellent (4 points): All key results, including descriptive and inferential statistics, are clearly reported and directly tied to the research question.
• Good (3 points): Most key results are reported clearly, though some minor details may be omitted or unclear.
• Satisfactory (2 points): Key results are reported but may be incomplete or unclear in some areas.
• Needs Improvement (1 points): Key results are missing or inadequately reported.
• Missing (0 points): The section is missing or extremely haphazardly prepared

6: Discussion

The Discussion section is the most important part of your report. This is where you interpret and explain the results of your experiment, relating them to your hypothesis, existing scientific knowledge, and the broader context of the field, essentially providing a deeper analysis of what your data means and its implications beyond just stating the findings. This section is the most important section of the lab report and allows you to demonstrate your understanding of the experimental process and showcase your critical thinking skills. In this section, you should:

• Interpret your results
• Compare your findings with your expectations
• Identify potential sources of experimental error
• Explain any unexpected results
• Suggest possible improvements for future studies

Interpreting your results means explaining how they help answer your main research question. State whether the results support your hypotheses.

• Did you measure what you intended to measure?
• Were your analysis methods appropriate for the type of data you collected?

Compare your findings with other studies, noting any significant differences in results.

• Are your results consistent with those of previous research or your peers? Why or why not?

A strong Discussion section will also address the strengths and weaknesses of your study.

• Did your study have strong internal validity or reliability?
• How did you ensure these aspects were met?

When discussing limitations, provide specific examples. For instance, if random error affected your measurements, identify the sources of error (such as imprecise equipment) and suggest how these could be improved in future studies.

Scoring Rubric: Discussion (24 points)

(8 points): Clarity and Organization    

• Excellent (8 points): The discussion is well-organized and flows logically from one point to the next. Each section is clearly written with no ambiguity.
• Good (6 points): The discussion is mostly organized, but some sections may be unclear or lack smooth transitions between ideas
• Satisfactory (4 points): The discussion is mostly organized, but some sections may be unclear or lack smooth transitions between ideas
• Needs Improvement (2 points): The discussion is mostly organized, but some sections may be unclear or lack smooth transitions between ideas
• Missing (0 points): The section is missing or extremely haphazardly prepared

(8 points): Interpretation of Results    

• Excellent (8 points): Results are clearly interpreted, explaining how they answer the research question and relate to the hypothesis. Provides a thorough understanding of what the results mean in the context of the experiment.
• Good (6 points): Results are interpreted clearly, but some aspects may lack depth or connection to the hypothesis. The interpretation is mostly accurate.
• Satisfactory (4 points): Results are somewhat interpreted, but the explanations lack clarity or fail to adequately connect to the research question or hypothesis.
• Needs Improvement (2 points): Results are poorly interpreted, with weak or unclear connections to the research question or hypothesis.
• Missing (0 points): The section is missing or extremely haphazardly prepared

(8 points): Identification of Experimental Errors

• Excellent (8 points): Identifies specific sources of experimental error with detailed explanations and how they may have affected the results. Discusses random and systematic errors thoroughly.
• Good (6 points): Some sources of error are identified, with explanations provided, but a few minor errors or their impact may not be fully addressed.
• Satisfactory (4 points): Some sources of error are mentioned, but they are either vague or not explained well in terms of their effects on the results.
• Needs Improvement (2 points): Experimental errors are poorly identified or missing. There is no clear discussion of how errors affected the results.
• Missing (0 points): The section is missing or extremely haphazardly prepared

7: Conclusion

The Conclusion section should be the final section of your lab report. In this part, summarize the key findings of your experiment, briefly highlight the strengths and limitations, and discuss the implications of your study for future research.

Scoring Rubric: Conclusion (4 points) 

(4 points): Restated key findings, brief reflection on meaning of results, proposal of future experiments/new experiments which build off this work.

• Excellent (4 points): Provides a clear, concise summary of conclusions, significance, and relevance to the research question.
• Good (3 points): Conclusions and significance are mentioned, but could be more specific or clear. 
• Satisfactory (2 points): Provides some conclusions, but lacks clarity or detail about significance.
• Needs Improvement (1 points): Conclusions are vague, unclear, or missing.

8: References (Optional)

The References section lists all cited sources, formatted according to a specific citation style (e.g., Journal of Physical Chemical).

9: Appendices (Optional)

The Appendices contains supplementary materials like detailed procedures, tables, or figures.

References

• An example lab report (Biology)
• Chemistry Lab Resources