United States Naval Academy
Mechanical Engineering Department
Format and Style Guide for Laboratory Reports
This document provides instruction on how to write a laboratory report and why. The terms,
“lab”, “laboratory”, and “experiment” are used as general terms to refer to investigations or
studies of any kind.
1. Introduction
The purpose of a lab report is to record the motivation, conduct, outcome, and analysis of an
experiment for future reference. The most important question to keep in mind when writing a
lab report is:
Could someone do this experiment, using only my report and references, and
under similar conditions produce similar results?
Explicit is the idea of what information should be included (all details necessary to conduct the
experiment), but implicit is also the idea of what information shouldn’t be included (any
information that is not essential to the conduct of the experiment and/or could otherwise distract
the reader).
A second and more fundamental purpose of documentation in general is to communicate the
process of going from data (e.g. experimental results), to information (e.g. trend analysis), to
knowledge (e.g. informed conjecture as to what happened and how it improves our
understanding).
2. Organization
Lab reports are divided into a minimum of five sections including the following:
1. Objectives – Why the lab was conducted
2. Procedures – How the lab was conducted
3. Results, analysis, and discussion – What came of the experiment and what was learned
4. Conclusions – Related to the objectives, a summary of what was learned
5. References – The sources of information used in conducting the lab and writing the report
Heading
The report heading must include the names of the students who contributed to the report (listed
in alphabetical order by last name), the course name and number, the section number, the date
submitted, and the title of the lab. The title of the lab should be in bold font, centered, and set
apart by a space above and below.
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Objectives
The questions you want to answer in this section are:
Why was this lab done? What where we trying to learn by doing it?
The objectives section should be a short, concise statement. The lab objectives (e.g. to compare
theoretical and empirical results) are not to be confused with the pedagogical objectives (e.g. to
familiarize students with experimental methods, or to teach them how to analyze data using
MATLAB, etc.). Although short, it is important that you consider carefully what, specifically,
you want to learn from the experiment.
Background (optional)
The question you want to answer in this section is:
What additional information would a reader need to know in order to understand and
appreciate the following analysis?
For labs that require some background investigation and/or additional explanation, that
information should be presented in this section. Again, the goal is to summarize concisely the
key findings of the research effort so as to provide the reader with the information and context
necessary to understand the following sections. Figures and tables are preferable to lengthy
descriptions.
Procedures
The questions you want to answer in this section are:
What was done? How was the experiment conducted?
Briefly summarize how the data was collected. It should be written in your own words, with a
clear, professional voice. It may help to think of it this way: if a fellow engineer asked you,
“What did you do in lab today?” the procedure section would be your brief but detailed
explanation. Generally, the section should be no more than a paragraph, but should include all
key details. It should reference but not reprint the procedures provided in an accompanying
handout. Figures and/or schematics of the experimental set up can be very useful in
communicating technical details.
Results, analysis, and discussion
The questions you want to answer in this section are:
What was the result? Was it expected? Why or why not? How does this result inform
our broader understanding?
In this section, present the information – preferably in figures, plots, and associated descriptions
– along with any other information pertinent to understanding your results (e.g. assumptions, test
conditions, aberrations, etc.). In addition to describing what happened, you must also try to
explain why, especially in cases when results are at odds with intuition, accepted values, or
analytical predictions.
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Note: Under no circumstances will “human error” be accepted as a source of deviation between
expected and experimental results.
As stated in the introduction, the analysis and discussion are really where the useful (knowledge)
is created from the less-useful (data). Your discussion should include a logical, well-reasoned
narrative and should clearly describe your thought process. After all, how you arrive at your
conclusions is just as important as what they are.
Conclusions
The questions you want to answer in this section are:
Did we answer the question(s) we set out to answer? If so, what did we learn? If not,
why?
The conclusions section is a summary of your findings and a brief explanation of their
significance. It absolutely must reference the objectives of the experiment, describing how the
objective was achieved. It should be quantitative (i.e. communicated with numbers) and
overarching. A kind of executive summary, the reader should be able to get the gist of the
experiment from reading this paragraph alone. The conclusion should not include general
musings, vague comments about what the students learned from the lab (pedagogically
speaking), or how the students feel about the experiment. Also, it should not contain any new
information.
References
As stated in the introduction, the purpose of documenting the experiment is to provide others
with enough information to recreate your experiment. As such, any reference material (e.g. lab
handouts, text books, library materials, websites, etc.) used during the conduct of the experiment
or the writing of the report (e.g. background information) must be documented so that it can be
found by others. References shall be organized into a list in accordance with the Chicago
Manual of Style author-date convention. A quick guide for in-text and end-note citations is
available here:
http://www.chicagomanualofstyle.org/tools_citationguide.html
As a general rule, you’ll want to provide a reference for anything that isn’t common knowledge.
For example, you need not cite a source when stating that in America, a right-handed traffic
scheme is used. However, if asked to provide examples of incidents involving Liberty Ships,
even if you’ve had a class that included a discussion of them, this would not be considered
common knowledge and thus you’d be required to cite the source of your information.
You may use endnotes, but not footnotes to cite your references. Make the report a separate
section from the appendices (Page Layout  Breaks  Next Page), and set the location for
endnotes at the end of the section, not the end of the document. See the sample laboratory report
for more details.
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Appendices
Appendices are to contain any information that might be useful to the reader but would disrupt
the narrative if included in the body of the report. For example, a computer code written to
analyze data would be helpful to the reader (certainly if he or she is your instructor), and thus
should be included in the report. However, inserting it in the body of the report would disrupt
the narrative and distract the reader. The same can be said for tables of raw data, amplifying
sketches, etc.
Appendices must be referenced in the body text, and appear in the order in which they are
referenced. They must also have a title and letter, appearing at the top of the first page of each
separate appendix, and a description such that the reader can have skimmed the report and still
have an appreciation for whatever is included. Unless instructed otherwise, include the lab
handout (as a separate appendix) for reference.
Note: Instructors may elect not to include the lab handout as an appendix. In this case you
would cite it as a reference as necessary.
3. Style
Lab reports shall be written in past tense as if you are documenting the experiment for the
purposes of academic posterity - for the record, so to speak. The voice of the narrative shall be
third person (e.g. “The car was released and rolled 4.5 feet”, not “We released the car…” or “He
released the car…”). Although admittedly awkward there is a reason for this. As engineers it is
our solemn charge to be objective; to fit our theories to the data not the other way around.
Writing in the third person removes the experimenter from the experiment, preserving our sacred
objectivity. As such, personal pronouns (e.g. I, we, our, etc.) are not permitted.
Also, as engineers we appreciate specifics whenever available. Work hard to fill your narrative
with numbers. Comparisons and descriptions should be quantitative. Don’t say, “The results
were close” because close can mean different things to different people. Instead, quantify how
close by providing the percent difference or percent error. Also, colloquial and/or flippant
speech is distracting. Don’t use verbiage like “…a decent job,” “almost made it,” or “the third
run sucked.”
4. Formatting
Above all, the purpose of report formatting is to present the information contained therein in the
most clear, concise presentation possible. The primary purpose of this guidance is to provide
you with a simple format, but one that provides “good order and discipline” so as not to distract
the reader. In general, all paragraphs are to be left-justified (as opposed to indented), and a space
inserted between paragraphs. Figures, tables, and equations should be separated from body text
by a space above and below for easy reading.
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Numbers, counting, significant figures
When it comes to including numbers and units in your description, the following guidelines
might be useful:
 Measured or calculated quantities are always given in numerical format with units where
appropriate (e.g. 4.2 m, 14.7 psia)
o Use abbreviations for units (e.g. lbf as opposed to pounds-force)
o There is no need to include a period after common units (e.g. lb instead of lb.)
unless required to avoid confusion.
 When counting, if the absolute value of the number is nine or less, spell out the word
o E.g. “During run number five…”
 When counting, if the value of the number is 10 or greater, use the number
o E.g. “During run number 10…”
Be sure to consider significant digits when reporting your findings and use scientific notation to
avoid the appearance of presenting data with more precision than was available. As a general
rule, you won’t be able to report values with more than four significant figures. Also, measured
or calculated quantities less than one, be sure to include a zero in front of the decimal point so as
not to have it mistaken for a period (e.g. 0.125 instead of .125 in).
Figures, Tables, Equations, and Appendices
The term figure is used to describe plots, images, diagrams – anything that isn’t a table. All
figures will include numbers (e.g. Figure 1, Figure 2, etc.) captions describing the figure, and
will be referenced somewhere in the body text (e.g. “Figure 1 shows…”). The caption for a
figure goes below the figure. You always want to describe the figure for the reader, describing
the axes and units, and state specifically what the figure tells you.
Graphs (figures!) should include at a minimum:
 Axes set to a range which minimizes whitespace and emphasizes the data
 Axis labels of legible size, including units when applicable
 A legend if more than one data set is plotted on a single graph
If multiple data sets are plotted on the same set of axes you should also consider using different
markers (e.g. circles, triangles, squares, etc.) and different lines for trend data (e.g. solid, dashed,
dotted, etc.) so that the reader can differentiate between data sets even if the report is printed in
black and white. Symbols should be used to show discrete data, and lines for continuous
functions like curve fits or equations.
Tables must also have numbers, column headings with units, captions including descriptions, and
must be referenced in the body text. The caption for a table goes above the table.
In general, you do not want to include calculations in the body of a lab report. Instead, provide
the governing equation. If calculations are needed to clearly explain the procedure or results,
provide them in an appendix. Equations must be offset by a space both above and below,
centered, and numbered. Equations are numbered sequentially, as they appear in the report and
must be referenced just like figures and tables. Use of equation writing software is preferable to
inline equations, e.g.:
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𝑘−1
𝑘
𝑇2
𝑝2
=( )
𝑇1
𝑝1
(1)
as opposed to
T2/T1=(p2/p1)^((k-1)/k)
An explanation of Microsoft Equation Writer is available on the department website as is a list of
shortcut keys and a very easy description of how to automatically format and number equations.
The term appendix applies to any figure, table, or amplifying text that appears after the list of
references. Appendices must be lettered (e.g. A, B, C, etc.), captioned including a description,
and referred to in the body text. Each appendix should start on a new page although some
information can be combined at the risk of wasting space (e.g. multiple tables of related
experimental data can be arranged neatly on the same page). Appendices also appear in the
order in which they are referenced.
To be clear:
 If it’s a table and it appears before the list of references: it’s a table
 If it’s not a table and appears before the list of references: it’s a figure
 If it appears after the list of references: it’s an appendix
5. Summary
The purpose of a lab report is to communicate to the reader the conduct of your report in the
most clear and concise terms you can. If ever you are uncertain about whether or not something
should be included or how something should be formatted, consider the quote attributed to
Professor Einstein (perhaps erroneously, but the message still resonates):
“Make things as simple as possible, but not simpler.”
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