A Quick Reference for Laboratory
Report Writing
Prepared for Covenant University
Engineering
By JASPER
Overview
This
document describes a general, adaptable format for laboratory
reports. The goal of laboratory reports is to document results and
communicate their significance. A good laboratory report does more
than present data; it demonstrates the writer's comprehension of the
concepts behind the data, and the significance of the results.
Typical
Components
-
The Title Page
must contain the name of the experiment, the full
names of lab partners, and the date.
Submittal information (course name, number and instructor) must also
be provided. Titles should be straightforward, informative, and less
than ten words (i.e. Not "Lab #1" but "Effect of
Grinding Time on Coffee Concentration"). Title page
The title page should include:
the name of the unit
the name of the experiment
the date you did the experimental work
the names and ID numbers of students in the group and
the name of the lab.
-
The Abstract summarizes
four essential aspects of the report: the purpose of the experiment ,
key results, significance and major conclusions. The abstract often
also includes a brief reference to theory or methodology. The
information should clearly enable readers to decide whether they need
to read the whole report. The abstract should be one paragraph of
100-200 words (the sample below is 191 words). The
abstract is often written last.
-
The Introduction states
the objective and scope of the experiment (or report) and provides
the reader with background to the experiment. The relevance and
importance of the experiment should be explained. The Introduction
provides a preview of the content of the full report. From the
Introduction, the reader should understand why the study was
performed.Introduction
This section introduces the reader to the experiment and briefly outlines theory and background information relevant to the experiment. You need to state any relevant laws, equations and theorems you will be using or investigating, and you need to explain the different analyses used, such as nodal analysis and mesh analysis.
Note
on Verb Tense
"The
objective of the experiment was..."
"The
purpose of this report is..."
"The
Ideal Gas Law is
..."
"The
Spectrophotometer measures ...
Background
(or Theory)
This section explains the
scientific principles that apply to the experiment and are relevant
to the analysis and interpretation of results. The background or
theory section should explain relevant equations as well.Aim
This section states the aims of the experiment. In any experiment, you aim to
do something.
For example, you aim to verify, to
investigate, to measure, to determine, to compare or to calculate.
Use the verb form starting with 'to' (eg 'to investigate').
Avoid the noun form which often ends in '-ion' (eg 'investigation').
Aims can be written either in point form or in complete sentences.
Example in point form
Aims
To measure the resistance of a specimen of wire.
To determine the resistivity of iron.
Example in a complete sentence
Aim: The aim of the experiment is to determine the resistivity of iron by measuring the resistance of a specimen of wire.
Choose the better wording from these examples of the aim section from two
student reports.
Aim
To investigate the effects of passing electric current through water.
An investigation of the effects of passing electric current through water.
Aim
The aim of the experiment was to verify Kirchhoff's Voltage Law.
Verification of Kirchhoff's Voltage Law.
Methods and Materials (or
Equipment)
This section provides the
source (company name and location) of all materials used, and the
model and manufacturer for all specialized laboratory equipment, and
a description of all methods of measurement. If a standard published
method is used, it must be referenced appropriately.Method
This section briefly reports the steps that you followed in carrying out the experiment. Do not repeat word for word what is in the lab notes but concisely summarise in your own words the key steps which were taken in the experiment.
The Method section describes what was actually done and so the verbs are usually written in the past tense, passive voice (for example, were connected, was measured, was calculated).
When you carry out an experiment, you usually follow a set of instructions. Here are the instructions for an experiment to determine the density of a steel sphere.
Example
Determination of the density of a steel sphere using a balance
First find the zero reading of the balance.
Then put the sphere in the left pan and put weights into the right pan to bring the pointer to zero and obtain the apparent mass.
If you were writing up the Method section, you would have to change these instructions to a report of what was done. These instructions might then be reported as follows.
Example
Method
First the zero reading of the balance was found. Then the sphere was put in the left pan and weights were added to the right pan to bring the pointer to zero. In this way the apparent mass was found.
In this Method section, the verbs are was found, was put, were added and was found which are all verbs in the past tense using the passive voice.
Change the verb in the instruction to the past tense passive form. For example: change find to was found.
Choose the better of these two examples from the Method section of two student reports.
Method
Connect four resistors with a 10 V supply and measure the open circuit voltage, and the short circuit current between A and B. Determine the voltage and resistance of the Thevenin equivalent circuit.
Method
Four resistors were connected with a 10 V supply and the open circuit voltage was measured. The short circuit current between A and B was also measured. The voltage and resistance of the Thevenin equivalent circuit were determined.
-
This section describes
the process in chronological order. Using clear paragraph structure,
explain all steps in the order they were performed. If the procedure
is properly described, another researcher should be able to duplicate
the experiment.
The procedure is always
written in past tense and passive voice.
Correct: Ground CacO3 was weighed on an analytical balance.
Incorrect:
We weighed ground CacO3 on an analytical/weighing balance
You weigh CacO3 on an
analytical/weighingbalance
Weigh the CacO3 on an
analytical/weighing balance
It should not be written
in the same format as a laboratory handout, which instructs
the experimenter to perform a series of steps.
-
This section presents the
findings and interprets their significance. All results should be
explained, analyzed, and interpreted.Results and Discussion
Note that sometimes in lab reports it may be more appropriate to present the results in one section, called Results, and then to discuss them in a separate Discussion section.
In the Results and Discussion section, you present your results and discuss them by:
commenting on the results obtained
interpreting what the results mean and
explaining any results which are unexpected.
You present the measurements made in the experiment and you then compare your measurements to the calculations you made in your preliminary work or the published theoretical values.
You need to:
identify any discrepancies and
to state them as a percentage.
You also need to:
identify any sources of error in your measurements and
if possible, suggest how your experiment could have been performed more accurately.
What should you aim for?
Clear comparisons made between the calculations and the measurements with the discrepancy expressed as a percentage.
Good explanation of the possible reasons for the discrepancy and the possible sources of error in the measurements.
Example
Here are some useful expressions to use if your measurements correspond well with your calculations:
The measurements are consistent with the preliminary calculations.
The measured values agree well with the calculated values.
Example
Here are some useful expressions if your measurements do not correspond well with your calculations:
The measurements are significantly different from the preliminary calculations.
The measured values do not agree well with the calculated values.
Example
Here are some useful expressions for explaining the source of errors:
The discrepancy may be due to human error.
The difference may be the result of incorrect calibrations.
Analysis and Interpretation
What
do the results indicate clearly?
What
is the significance of the results?
Compare
expected results with observed results. What ambiguities exist
between the expected and observed results? Logical explanations
should be provided.
Was it avoidable? Was it
a result of equipment? If an experiment was within the
tolerances, there can still be a deviation from the ideal. If the
flaws result from the experimental design explain how the design
might be improved.
When comparing observed
results to expected results, the expected results should always be
based on sound scientific principles. These principles, along with
relevant equations, should be provided in the Theory (or Background)
section of the report.
It is desirable to
compare your results to published results of related studies. If
published information is unavailable, you may compare your results to
those of other teams in the class.
This is particularly
useful if a new or original design has been used.
The results are often
conveniently expressed using graphs, figures, and tables, but must
always be explained in the text.
It is never acceptable to
present data in a graph or table without explaining them. Results
must always be explained and analyzed in the text.
It is never acceptable to
simply present a table without specifically directing the reader to
it in the text.
Sample calculations and
raw data should be put in an Appendix. Refer to these Appendices in
the report by directing the reader to them for the specific
information provided (never just leave it up to the reader to
discover the appendices).
-
In
this section the significance and implications of the findings are
summarized. The conclusions must be consistent with the
stated objectives and with the results. The conclusion might also be
a place to discuss weaknesses of experimental design, and what future
work needs to be done to extend the conclusions.
All recommendations for
future work should be positive, relevant, constructive, useful, and
practical.Conclusions
This section states whether the aims of the experiment were achieved or not, and briefly summarises the key findings.
In the Conclusions of this kind of report you need to:
comment on how closely your measurements and calculations agree and
summarise the main reasons for any discrepancies.
Choose the better of these two examples from the Conclusions section from two student reports.
Conclusions
Despite some errors, the law was verified.
Conclusions
Kirchhoff's current and voltage laws have been verified. The superposition theorem for a two source network has also been verified. The experimental results were always within 1.1% of the calculated values. The discrepancies may be due to ... ... ...(provide a reason here!).
-
References must be
included if information from outside sources is included in the
report. Any material or information taken from another source must
be specifically cited (footnoted) in the text, and the references
should appear at the end of the document in endnote format. The
References section is not simply a reading list of books and articles
on the subject.
-
The Appendices should
include such elements as raw data, calculations,
graphs pictures or tables that have not been included in the report
itself. Each kind of item should be contained in a separate appendix.
Each Appendix should have a letter designation (Appendix A, Appendix
B, etc.) and a descriptive title. For example, the results section
might begin by noting: "Laboratory Data for Coffee Concentration
as a Function of Grinding Time." Make sure you refer to each
appendix at least once in your report.
Format Requirements
It
is important to prepare a laboratory report that reflects a high
degree of professionalism. Keep in mind that this is a written
record and is a reflection of your professionalism and competence.
Every course instructor, boss, company, and agency that you work with
throughout your career will have different format requirements, but
you must follow them! All format guidelines are established to
produce readable, visually appealing, clearly structured documents.
Laboratory Report Format
Using an impersonal style in lab reports
Since scientific writing is usually presented in an impersonal, objective
manner, the personal pronouns I, we, and you are generally not used in lab
reports. There are several ways of avoiding using personal pronouns.
Use passive sentences
Instead of
Write
We tested the specimen.
The specimen was tested.
I measured the resistance.
The resistance was measured.
Use third person pronouns
Instead of
Write
I found that...
It was found that...
We concluded that...
It was concluded that...
Use the report or its various sections as actor
Examples:
This report presents...
The results show...
Prepare
all documents using a hand writen,using A4 PAPER.
Paragraphs
should be double spaced with the first line indented 0.5 inches.
Use
headings to provide structure and enhance readability. Headings
should be in the bold format.
Skip
one line above and below headings.
Use
page numbering (pages before the Abstract should not be numbered.
The Abstract starts on page 1). Pages should be numbered at the
bottom of the page in the center.
Figures
and Tables must be numbered.
Equations
must be centered in the line and numbered, with the equation number
right-justified.
References
cited should be provided as endnotes. All references should be
complete, and in standard bibliographic format.
Books
Author,
Title, Edition, Volume, Publisher,City, Year.
Cole,
P.J., Haiku of Philadelphia, 2nd ed., William C.
Brown, New York, 1996.
Edited Books
Editor
(ed.). Title, Edition ed, Volume. Publisher, City, Year.
Bergey,
D.H., J.G. Holt, and N.R. Kreig (ed.), Bergey's Manual of
Determinative Bacteriology., Williams and Wilkins, New York,
1984..
Reference format for Lecture Notes
and Handouts
Author,
Title, Course, Institution, City, Year.
Sheil,
J, Laboratory Handout: Determination of Paint Composition,
Experimental Methods in Egyptology, Columbia University, 1986.
Reference format for Journal
Articles
Author,
Title, Journal, Volume(Issue) Year, Pages.
S.
Farrell, J. A.. Newell and M. J. Savelski, Introducing Chemical
Engineering Students to Product Design through the Investigation of
Commercial Beer, Chem. Eng. Educ., 36(2) 2002, 11-20.
Manchester United manager David Moyes has said that he may not sign
anyone new before the end of the transfer window on September 2. His
pursuit of Cesc Fabregas has all but come to an end, while bids for
Marouane Fellaini and Leighton Baines were strongly rebuffed by Everton.
We Are Separated
He Is the Only Way to God
