Lab reports, like other kinds of writing, have an organized format. The format depends on how the report will be used and what headings your readers expect to find. For example, in industry, a design engineer reading a report may be concerned only about a test's results and not the procedures or equipment used. On the other hand, a peer in your class reading your report may need to know what equipment you used and how you conducted your test.
Most lab reports follow a general format. However, you may be required to use different headings or to present your data in a different order. You may also be required to include or exclude specific information. Be sure to check with your instructor before using the format depicted here.
Transmittal letters often accompany reports and inform readers of a report's context. Typically, the letter includes information not found in the report. For example, when turning in a lab report, you would include the report's title, what assignment it fulfills and the due date. Check with your instructor to determine whether or not you should attach a transmittal letter to your report.
A lab report should always include a title clearly identifying the lab. A title should be descriptive and accurate, but not wordy, verbose or too terse.
The following are examples of strong titles:
- An Experiment to Test the Fatigue of Paper Clips
- An Experiment to Test the Elastic Properties of Composite A Using Vibration Techniques
The following are examples of weak titles:
- A Fatigue Experiment
- An Experiment to Test the Fatigue of Paper Clips by Repetitive Bending
Readers may expect, and require, a list of all the equipment used in a test. This list includes the equipment's name, as well as the equipment's number. Listing your equipment ensures that you use the same piece of equipment throughout a test. Check with your instructor to determine whether or not this information should be included under its own heading or with Procedures/Methodology.
Under the Procedures/Methodologies heading, you should describe each step of the lab test. You might also document your goals and the steps taken to accomplish those goals. To determine which heading to use, Procedures or Methodologies, check with your instructor.
In the Procedures/Methodologies report the steps, including any preparations, followed during a lab test. You should also document your goals and the steps taken to accomplish those goals. The materials and equipment you used may or may not be included here.
Procedures/Methodologies are extremely straightforward and typically written in the past tense. Here, you should not document the findings of a test -- that is, the results of a test. Instead, explain exactly what you did to get your results.
ASTM, The American Society for Testing and Materials, standards should be included under the Procedures/Methodology heading. These standards inform readers about how materials and samples were handled before testing. They also include materials' properties. The site below does not list standards, but it describes the ASTM organization and provides contact information.
Under the results heading, you should report what you found. Here, you may or may not include data interpretations. Some readers expect interpretations, or conclusions, to be a separate heading. Check with your instructor for what to include in your results.
In the results, document the test's outcome(s). Here, tell your readers what the test measured with exact data. You may also include calculations or equations.
Be brief when writing your results. If a lab has more than one finding, report the findings under separate subheadings. Typically, in the results, you present the numerical data of your findings. Be sure not to include details about how you performed a lab. Instead, report only the outcome(s). For example, "The results of the three tests are x, y, and z."
If you are required to interpret your data here, explain how you arrived at those results. You should also include why any data may be incorrect, such as odd occurrences during the test.
Under the conclusions heading, you should comment on the outcomes of a test. Here, you might also speculate about the implications of the results or even about the methods used to obtain the results. Some readers may not expect conclusions. For example, design engineers reading a report may interpret, or make conclusions, about results themselves. As a student, you may need to interpret, or make recommendations about, the results for your readers.
Under the conclusion heading, interpret the lab's results. If the results are correct, provide the reasons why. If the results are incorrect, discuss what went wrong. The conclusions also speculate about the implications found or even the methods used to obtain results.
Your conclusions should note what was good or bad about your test. If the results are not exactly what you expected, propose reasons why your results turned out as they did. When you comment on procedures, ask yourself questions such as what are the advantages of this method compared to other ways? What are its deficiencies, or difficulties compared to other ways?
Lab reports may or may not include references. If you use information from the course textbook, cite it as a reference. You should also cite any standards used from ASTM, The American Society for Testing and Materials, or ACI, American Concrete Institute. Check with your instructor to determine which reference style you should use.
Graphics provide illustrated information to readers. In general, graphics are designed to make it easier for readers to understand your report. Deciding when to insert a graphic depends on the information you need to convey. For example, as you're writing your report, you find yourself struggling to describe a complex concept. Fitting your description within a few paragraphs is impossible, so you decide to create a graphic. Often, graphics are useful when concepts, designs, or processes are too complex or cumbersome to describe in written or oral form.