Writing a Formal Lab Report
Provided by the Academic Center for Excellence 2 Reviewed June 2008
o Use correct verb tenses. Many students become confused when trying to decide whether
to use past or present tense in their reports. The general rules for verb tenses are as follows:
The experimental procedure has already been conducted, so use the past tense of the
verb when referring to it:
Ex: The purpose of the experiment was…
The compound was weighed to 5 g…
The report, equipment, and theory still exist, so use the present tense of the verb for
them:
Ex: The purpose of this report is… Bunsen burners are used…
o Be prepared for the lab. Before coming to the lab session, read the procedure in the lab
manual thoroughly. Write down a purpose, hypothesis, and a general plan for the procedure
you will follow and bring them to the lab with you. If you understand what you will be
doing before beginning, it will be much easier to take relevant notes during the lab and to see
what you will need to include in the report afterwards.
o Take good lab notes. When conducting the lab, it is important to write down all the
results that will be needed for the report as well as all observations, any materials and
equipment used, and anything out of the ordinary that may have happened. Notes should be
clear enough, so they are easy to review when writing the final report. Tables are useful for
keeping large amounts of experimental data in order, so you may want to include them in
your laboratory notebook. Good notes will help you to write an insightful and accurate
report.
o Don’t copy the laboratory manual. If you are working from a lab manual, it can be used
as a helpful guideline when explaining the procedure and the purpose of the experiment;
however, you should not copy it word for word. By using your own words, you are showing
the instructor that you have a good understanding of what is being done and why it is being
done.
o Write about what really happened in the experiment, not what “should” have happened.
Instructors grade lab reports based on understanding of the experiment rather than the
results achieved, so if things did not go exactly as planned in the lab, resist the temptation to
lie about the results in the report. Instead, try to explain what might have gone wrong and
suggest ways the experiment might be improved in the future.
o Use peer-reviewed sources for research. If background research is needed for the report,
only credible sources should be used. Online scientific and medical journals are good
internet sources for this type of report; in contrast, unofficial websites that are not peer-
reviewed should be avoided. Textbooks and encyclopedias are also helpful for explaining
theories or concepts used in the experiment.