Laboratory Report Guidelines: Fall 2011 General Chemistry
Written documentation of scientific work is one of the most important methods for scientists to
communicate their results. A written report documents the experimental findings with enough
detail to duplicate the original results. Scientific reports are written in a standard format that
includes an introduction, a description of the methods and materials used, a summary of the
results, and a discussion of these results. Scientific papers published in journals also include an
abstract and a bibliography. The ability to write a laboratory report in standard scientific format
is a valuable communication skill because it provides access to the vast body of original
scientific research. The laboratory reports in the general chemistry laboratory serve as an
introduction to this process.
“Scientific explanations” can be broken into three major components: claim, evidence and
reasoning.
The claim is a statement or conclusion that answers a question(s).
The evidence is the scientific data that supports the claim. The evidence should be both
appropriate and sufficient. By appropriate we mean it is directly relevant to the current problem
and allows someone to independently evaluate the claim. Sufficiency stresses the idea that you
should not just rely on one piece of data, rather multiple pieces of evidence (including
observations) can make much stronger support for claims.
The reasoning is the justification for why your data (and observations) count as evidence to
support your claim. Often, this requires a discussion of scientific principles and you can also
introduce other studies to build up your reasoning.
Lab Report: a written laboratory report is required for each experiment in the general chemistry
laboratory course. Laboratory reports should be typed and can take various forms. The list below
is generally used in chemistry:
•
•
•
•
•
•
•
Name
Lab partner name
TA name
Date of lab work
Title of Experiment
Introduction: The introduction should contain the goals of the experiment and a brief
summary of any key background information and concepts needed to understand the
experiment. This is a good place to summarize safety precautions that are important to
completing the lab safely.
Procedures: this section describes an individual's experiment, NOT a reproduction of
the procedures listed in the lab handout. You can write it as a narrative, but it should
have complete, meaningful sentences. Often you can refer to the procedure, as in “The
following procedures were taken from the procedure” http://icn2.umeche.maine.edu/newnav/NewNavigator/labs/Alum__6174.htm, accessed on
September 06, 2011. The following changes were made during the experiment…” If you
•
are asked to design an experiment, this is where you would summarize the procedures
you designed.
Results: this section includes evidence. Calculations can be hand written if necessary as
shown below. Graphs, Figures, and tables can also be included in this section (see
below). Answers to any lab questions also belong in this section. Data that was collected
and observations that you’d like to use as evidence should be presented in this section.
Sample Calculation:
Sample Table of Unknown Observations:
Water
Unknown
Vinegar Alkaline
Soluble
Yes1
No
Nonbubbles alkaline
No 2 Bubbles alkaline
Yes3
No
NonBubbles alkaline
No 4
No
NonBubbles alkaline
Yes5 Bubbles
•
•
Nonalkaline
Discussion: the discussion section can be a separate section or integrated into results (i.e.
Results and Discussion). The key part of this section is to present scientific reasoning
using your evidence to support your claims. This is a key section that your TAs will be
looking at when grading your lab report. If error is a factor in the precision or accuracy of
your evidence and hence your results, this section is a place to discuss this.
Conclusion: This section provides the highlights of your claims, evidence, and reasoning,
This section is optional, but is often used by authors to focus attention on key factors in
the claims, evidence, and reasoning used in the report.