How to Keep a Laboratory Notebook
Laboratory notebooks are legal archival documents where scientists record exactly
what they did and observed for a given experiment on a given day. Lab notebooks should
include a detailed account of experimental procedures and all raw data collected.
All laboratory activities must be recorded in a complete and well-organized manner in a
bound notebook with consecutively numbered pages. Below are guidelines for how to keep
a good laboratory notebook. While the organization described in these guidelines is
important to adhere to, keep in mind that notebooks are documents scientists write AS
THEY ARE WORKING, and thus no one expects them to be perfectly organized and error
free. Writing observations outside of the lab period and re-copying your notebook
pages to make them “prettier” is not appropriate.
1. On the Front cover should be your name and the course number.
2. On the inside of the front cover should be your locker combination, and contact
information in case you lose your lab notebook
3. The first page should be a map of the lab where hoods, safety devices, broken
glassware depository, waste disposal, are clearly labeled.
4. Leave the 2-3 pages of your notebook blank, for use as a Table of Contents.
5. When writing in your notebook:
a. Always use ink
b. Write legibly using simple declarative sentences
c. Write directly in your notebook, not on a piece of paper first
d. Never use white-out. If you make an error simply draw a line through the
mistake, and re-write the correct text. For example: 2.908g 2.928g
e. All experiments must be written in your notebook on consecutive pages
6. NEVER remove notebook pages.
7. If you use a computer for data analysis (i.e. Graphs), sketch the graph in your
results section. Also include the name and location of the corresponding computer
file.
8. You will need to include the following elements: Sections A-D should be created
before lab. Section E should be created during lab, and Sections F and G,
Results and conclusions should be written after you have collected and interpreted
your data.
A) The date, and experiment title.
B) The “Purpose” section. In one or two sentences, summarize the experiment
you will perform and its scientific principles.
C) Equation section. For experiments involving chemical reactions provide a
balance equation. Give the name of each reactant and product, and create a
table listing the physical data such as molecular weight and density. Also
create blanks for moles used, grams used, and mLs used.
D) Procedure reference. Writing the entire procedure from the lab manual is not
necessary, but a reference to the procedure in the lab manual is required. Any
deviations from the procedure listed in the lab manual should be stated.
E) Data and Observations section. Record all data, observations (color changes,
temperature changes, formation of precipitates, gas formation, etc.), and
deviations from your stated procedure.
F) A “Results and Calculations” section. In this section, to be done at home, you
should summarize and provide your calculation and interpretation of your
results. Show your calculations, if calculations are part of the result. And
example would the percent yield. If some anomaly occurred (an unexpected
result, low yield, etc.) make an attempt to account for it. Where appropriate,
compare your results with those expected based on know facts, such as
density, or molecular weight.
G) Discussion/Conclusion: In his section the purpose should be restated with an
explanation about how well the purpose was accomplished. If the purpose was
to measure the density of aluminum, you should state that the density was
determined to be 2.78 g/mL, with a percent error of 5.1%. Reasons for the
variance of your result with the literature value should be included, as well as
how you could improve in results if your were to run the experiment again.
Your instructor will grade your laboratory notebook before leaving lab.