Purpose
Laboratory reports are a vital part of the scientific process. Lab reports should communicate the important
work you have done in lab so that someone who was not there can understand and replicate your results. They
also propose future studies and experiments or suggest alterations to pre-existing methods.
Lab reports should be written for someone who is familiar with the scientific field of study but has not
performed this experiment.
Organization
Lab reports are commonly organized into 7 sections:
• Abstract
• Introduction
• Material and Methods (or Procedures)
• Results
• Discussion
• Conclusion
• References
This structure is general and can be changed depending on
your instructor’s preferences.
Abstract
The abstract serves as a synopsis or summary of the experiment. It is concise, often around 250 words, and
briefly summarizes the experiment, results, and significance of the study. In general, an abstract would include
a sentence or two for each of the following points:
1
Background/Objective
2
Hypothesis/Aim
3
Methods
4
Results/Discussion
5
Conclusion
Laboratory Reports
apu.edu/writingcenter/resources
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For more help on this section, see the
Writing Center’s handout on abstracts.
Abstract
Accuracyandprecisionareimportantscienticconcepts,andunderstandingthe
differencebetweenthetwoisimperativeforthebuddingstudent.Additionally,different
piecesofscienticglasswarehavevaryingdegreesofprecisionandaccuracy.Here,theaim
istodeterminewhichmethodofmeasuringliquidsismostprecise.Baseduponknowledge
frompreviousstudies,thepredictionisthatburetswillbethemostprecise.Thiswillbe
determinedbytakingthemassofwaterdeliveredbyeachinstrumentandusingdensityto
determinetheprecisevolume.Uponcompletionoftheexperiment,itwasdeterminedthat
volumetricpipetswerethemostprecise,delivering10.00ml±.01ml.Thisinformationwill
bekeyindecidingwhichglasswaretouseforfutureexperiments.
1
2
4
3
5
2
Introduction
The introduction provides the reader with relevant background information, explains the experiment and
what it aims to accomplish, and highlights its importance. Your introduction should include a purpose and
hypothesis because you will return to those in your conclusion to evaluate the experiment. Good introductions
cite relevant, primary sources, such as journal articles, in order to give reliable background information. Note:
Your textbook is a secondary source, not a primary source!
Perhaps the most effective way to write an introduction is by using the funnel method. Begin with the most
broad point of interest in your topic before narrowing your information down to specific details. For example,
the following figure reflects a lab report about sugar and dental hygiene.
In this scenario, the first point is about sugar and dental hygiene, in general. To become more specific, the
second point highlights past literature on pediatric dental hygiene. Then, a problem, such as poor dental
hygiene in children, is raised. The last points include the hypothesis and a preview of content to be discussed
in the remainder of the lab report.
Be sure to check with your professor for any specific instructions regarding content and formatting!
Materials and Methods
This section is important as it explains the precise way in which
the experiment took place so that the reader can repeat it if
desired. However, your materials and methods section should
NOT look like your lab manual, and it should avoid lists. It is
written in a past tense narrative form that avoids the use of the
first person. Furthermore, you must assume the audience has
basic knowledge of lab techniques. For example, instead of
detailing the entire process of a titration, you can simply say
“0.1M NaOH was titrated against an HCl solution of unknown
concentration.” However, if you change a standard procedure, it
should be noted within this section. Also, include as much detail
as possible about the materials used in your experiment (exact
name of the material, concentration or mass, volume, company
of origin).
Bad Example:
The following chemicals were
combined into a test tube using a
pipette: bovine serum albumin,
NaOH, and Bradford reagent.
Good Example:
An Eppendorf tube was filled with
1 mL of 2 mg/mL bovine serum
albumin (Sigma-Aldrich, Cat#XX-XXX),
3 mL of 0.15 M NaOH (Sigma-Aldrich,
Cat#XX-XXX), and 1 mL Bradford
reagent (Sigma-Aldrich, Cat#XX-XXX).
Sugar, Dental Hygiene
Past studies on pediatric dental
hygiene
Children are showing an increase in
poor dental hygiene.
An increased consumption of candy
may cause a greater number of
cavities in children.
Experimental Overview
General Information
Specific Information
Problem or Issue
Hypothesis
Experimental
Overview
3
Results and Discussion
This is where you include all of your results and any relevant figures and tables (properly labeled). The results
still utilize the narrative form found in the material and methods section. Your tables and figures should be
able to explain your results without text, and your text should do the same without figures and tables. The two
should parallel each other. In chemistry, the results and discussion are written as one section. In biology, they
are written separately.
In the discussion section, use underlying theories to explain how you achieved your results as well as what they
might imply. Include any errors and how they may have affected your data. Note: Do not just report results,
but analyze them. This means discussing trends, shapes of graphs, any outliers, implications of the data, and
comparisons to known values or theories. Also, a discussion regarding the certainty of your results is important.
Pay attention to what your instructor requires for this section.
Conclusion
This is different from the results/discussion as the conclusion explains the results
from the perspective of the entire experiment. Here, return to the original
objective or hypothesis of the experiment. This is a good place to reference back
to the introduction and past studies regarding this topic. Does this experiment
contribute to or further the current research? If not, give reasons why. Include
suggestions for further studies in this section. Note: This section can be omitted
in shorter lab reports. Refer to your instructor’s preferences on this.
References
Make sure to include any citations in the documentation style your professor prefers. Reference managers,
such as Mendeley, can be helpful for this section.
Rev. 04-2018
Quick Tips
• Writing your lab report in an order that
makes sense to you may help all of your
points come together. Below is a suggested
order for writing your report.
• Methods
• Results
• Introduction
• Discussion
• Conclusion
• Abstract
• Title
• References
• Understand the difference between a
purpose and a hypothesis.
• Purpose = an explanation of why the
experiment is useful
• Hypothesis = what you are trying to
explain through testing
• Instead of saying that one variable affects
another, explain how it affects it. Are they
inversely proportional? Directly proportional?
• Titles of lab reports should be descriptive
and detailed.
• Properly label all figures, tables, and graphs
• In general, a table title should be above
the table and a figure table should be
below the figure. Make sure to check with
your professor!
• Know the difference between affect
and effect.
• Affect = verb
• Effect = noun
• Use academic hedging —the study "suggests"
not "proves."