The Parts of a Laboratory
Introduction:› What is the context in
which the experiment takes place?
The primary job of any scientific Introduction is
to establish the purpose for doing the experiment that is to be
reported.› When scientists do research, the main purpose that
guides their work is to contribute to the knowledge of their field.›
That's why the scientific context they establish in their introductions
usually consists of summarizing previous research reports published
in the field.› A scientific contribution to the knowledge of the
field can be understood only within the context of what other
scientists have done.
The main purpose of writing a lab report, of course,
is not to contribute to the knowledge of the field; but to provide
you the opportunity for learning.› That's why it's important to
begin the lab by establishing that learning context.› The learning
context provides a way for you to situate the lab report within
the overall purpose for doing the lab in the first place:› to
learn something about the science of the course you are taking.
An effective introduction to a lab report typically
performs the following tasks, generally in the order presented:
|it establishes the learning context for the
||saying what the lab is about, that is, what
scientific concept (theory, principle, procedure, etc.)› the
researcher is supposed to be learning about by doing the lab;
||giving the necessary background for the learning
context by providing
pertinent›information about the scientific
concept (this information can come from the lab manual,
the textbook, lecture notes, and other sources recommended
by the lab manual or teacher; in more advanced labs you
may also be expected to cite the findings of previous scientific
studies related to the lab).
|it provides the primary goals of the lab by:
||presenting the objective(s) for the experimental
procedure (what is being done in the experiment, such as to
measure something, to test something, to determine something,
||defining the purpose of the lab (the way the
experimental procedure is linked to the learning context).
|it offers a hypothesis for the experimental
||stating the hypothesis, or the best estimation
of the outcome of the lab procedure; and
||explaining the scientific reasoning that leads
the researcher to that hypothesis.
Materials and Methods:› What did you do
and how did you do it?
There are various other headings one may find for
this section of the report, such as "Experimental Procedure,"
"Experimental," or "Methodology."› Sometimes
Materials and Methods may be separated in different sections.›
But however it is titled, the main tasks of the Materials and
Methods are to describe (1) the lab apparatus and the laboratory
procedure used to gather the data and (2) the process used to
analyze the data.
Materials and Methods takes the reader step by step
through the laboratory procedure that the experimenters followed.›
The rule of thumb in constructing this section is to provide enough
detail so that a competent scientist in the field can repeat,
or replicate, the procedure.› The challenge, however, is to do
so as efficiently as you can.› This means, for example, not including
details that the same competent scientist already knows, such
as descriptions of standard procedures that most everyone in the
field would already be familiar with.
to the Materials and Methods of the Annotated Sample Lab Report
Results:› What did you find?
This is the heart of the scientific paper, in which
the researcher reports the outcomes of the experiment.› Report
is a key word here because Results should not contain any explanations
of the experimental findings or in any other way interpret or
draw conclusions about the data.› Results should stick to the
facts as they have been observed.
Generally speaking, the Results begins with a succinct
statement (a sentence or two) summarizing the overall findings
of the experiment.› After that the Results integrates both visual
(graphs, tables, drawings) and verbal (words) representations
of the data.› The verbal descriptions consist of series of findings
(general statements that summarize or give the important point
of a visual) and support for the findings (further details about
the data that give pertinent information about the findings).
Discussion:› What does it mean?
The purpose of the Discussion is to interpret your
results, that is, to explain, analyze, and compare them. ›This
is the point at which the researcher stands back from the results
and talks about them within the broader context set forth in the
Introduction.› It is perhaps the most important part of the report
because it is where you demonstrate that you understand the experiment
beyond the level of simply doing it.› Do not discuss any outcomes
not presented in the Results.
The Discussion section often begins by making a
statement as to whether the findings in the Results support or
do not support the expected findings stated in the hypothesis.›
It's important to make such a comparison because returning to
the hypothesis is crucial to basic scientific thinking.› The statement
of support or non-support then leads to the next logical issue,
an explanation of why the hypothesis was or was not supported
by the data.› The explanation might focus on the scientific reasoning
that supported the original hypothesis (based on the scientific
concept on which the lab is founded) and on changes to or errors
in the experimental procedure and how they could have affected
the outcomes.› The Discussion also provides the opportunity to
compare the results to the research of others.
Conclusion:› What have I learned?
The Conclusion returns to the larger purpose of
the lab, which is presented as the learning context in the Introduction:›
to learn something about the scientific concept that provides
the reason for doing the lab.› This is where you demonstrate that
you have indeed learned something by stating what it is you have
learned.› This is important because it helps you to understand
the value of the lab and convinces the reader that the lab has
been a success.› It's important, then, to be specific, providing
details of what you have learned about the theory or principle
or procedure at the center of the lab.
Abstract:› What is the essence of the
The Abstract is a miniature version of the lab report,
one concise paragraph of 80-200 words.› Its purpose is to present
the nature and scope of the report.› In the scientific literature,
abstracts must be stand-alone documents, whole and self-contained,
because they are often published by themselves in research guides.
To create a miniature version of the report, abstracts
usually consist of one-sentence summaries of each of the parts
of the report (sometimes two sentences are necessary for especially
complex parts).› And those sentences are arranged on the order
that the parts come in the report:› Introduction, Materials and
Methods, Results, Discussion/Conclusion.
Title:› What is the report about?
The main job of the title is to describe the content
of the report.› In science, a title usually tells the reader what
the subject of the experiment and the key research variables are,
and it often gives an indication of what research methodology
was used.› Titles are especially important to scientists because
articles are typically indexed according to key words that come
from the title.› So when scientists are searching for research
articles, it is those key words that lead them the articles they
need.› It's necessary, then, that titles be fully informative
about the content of the report.
References:› What sources were used?
This is a list of the references that were cited
in the lab report, including the lab manual, any handouts accompanying
the lab, the textbook, and sources from the scientific literature.›
The format for references differs in different fields and even
within the same field.› It's important that you check with you
teacher or lab manual to find out what is expected of you.
Appendices:› What additional material
Appendices are places where you put information
that does not deserve to be included in the report itself but
may be helpful to some readers who want to know more about the
details.› The kinds of information you might find in an appendix