How To Keep a Lab Notebook
The Laboratory Notebook
Maintenance of an acceptable laboratory notebook will be emphasized in the General Biology
Laboratory courses. Record keeping and data interpretation are skills which you will use throughout
your career be it in science or any other field. The ability to prepare an adequate and reliable record
of results is a fundamental requirement for all successful experimental work.
The most important criterion for an acceptable lab notebook is that the record be complete enough
for a second person to be able to follow your experimental work, thus being able to repeat the
experiment and to obtain the same results. The record must be written while you do your work.
Your records should reflect your work so well that any odd results can be interpreted later, even if
you don't notice them at the time. Later, you can do calculations, etc. If you find yourself unable to
figure out where a mistake or error has occurred, you are likely NOT keeping an effective
notebook.
How to Keep a Laboratory Notebook:
From the beginning of this term, you will be expected to start keeping a laboratory
notebook. As the term progresses, you will learn more and more of the details concerning how
to keep a professional style notebook. This includes using clear handwriting in your notebook;
illegible labs will not be graded!
Lab notebooks should be written in third person…if you don’t know what this means seek help
from an
Communications professor.
1. You will need a composition style lab notebook.
2. You should organize your lab notebook in the following way:
a. Put your NAME, course number, and lab period should be on the outside cover.
b. Page 1 and the first few pages are the table of contents of your lab notebook; fill in the date
and title as you go through the semester. Make sure to add the page numbers as you go.
Date
Lab # and Experiment
Page #
Name
c. All entries should be made in Pencil. Pencil will not run if it gets wet unlike ink. However, do
not erase errors, do NOT use white-out on errors, do NOT scribble out errors, do not make your
lab notebook look like a coloring book from a 3 year old. Simply cross off the mistake with a single
line.
i. Example: Place 3 grams of NaCl in a beaker and dissolve in 200 250 ml of water.
d. Record all data in your notebook at the time that it was performed. Do not record information
on paper towels (they get thrown away or spilled upon) or scrap pieces of paper (that get thrown
away or spilled upon). Do not rely on your memory. Simple transposition of numbers can throw
off calculations and the error will propagate itself throughout the lab.
e. Provide as much detail as you can. What color are the reagents? What crystal type are the
solids. Baby powder and salt are both white solids, but they look nothing alike – describe, describe,
describe!!!! What happens when you mix reagents together? Does the product form immediately?
Where any gases emitted? What does the product look like?? Be thorough. It is not uncommon for
a seemingly trivial observation to become important later in the experiment.
f. Organize your data in a straightforward manner. Keep the notebook in chrono logical
order. Make sure that all sections in your lab notebook are clearly labeled. Use tables where
applicable to better present your results. Draw schematics or flow diagrams to simplify a long
procedure. Be neat!!!! This requires planning, planning, planning, and more planning BEFORE you
come to lab. The shell of your notebook should be filled out before walking in the door. Leave
enough space for observations and calculations that you might have to perform during the lab.
Your lab manual will constructed using two main submissions each week.
1. Due Before Class Starts: Prelab Entries: Part of your grade for the lab portion of this class will be
based upon your pre-lab preparation. Depending on the experiment, this may or may not include a
separate online or in class pre-lab quiz. Regardless, you will be expected to come to lab with your
notebook prepared for the day’s investigation. After the Table of Contents, you can sequentially
start keeping information from each lab. See below for the recommended format for keeping
information in lab. The organization of the pages for a particular lab should contain the following:
a. Title block – The Full experiment title and Lab number, Your Name, the date, page numbers of the
experiment and course number MUST be on every page of the notebook.
b. Objective Statement – A restatement of what BIOLOGICAL PRINCIPLE is being demonstrated.
c. Hypothesis Section – You should restate the hypothesis for each lab as well as add additional
information from your textbook.
d. Equipment – What materials are needed to conduct the lab? You should draw pictures of
apparatus(es) and look up those items you do not know.
e. Chemicals – This is a list of chemicals you will be using. You should write down formulas, if given,
important physical concepts and safety information. A table format is suggested.
f. Procedure/Methods – This is a full step by step re-writing of the procedure from the lab
manual/handout. It is designed for you to think about what you will be doing in the lab each week.
It should be detailed enough that you can conduct the lab WITHOUT THE LAB MANUAL, as that is
exactly what you will be required to do.
g. Calculations – The calculations should be laid out prior to the start of lab. This will include any
calculations you need to conduct as well as calculation of the theoretical yield.
CUTTING AND PASTING FROM THE LAB MANUAL IS NOT ACCEPTABLE AND WILL RESULT IN A
FAILING GRADE FOR THE LAB.
2. Due ONE week after the lab is completed for applicable experiments (before class begins):
a. Observations – What did you see happen? What color, smell, shape, texture, etc., did the chemicals
have? Did you notice bubbling, color changes, etc. This is not a section of the manual that has
numbers and data.
b. Data/Results – Data is any number you take from a measurement device (i.e. 12 cm, 14.5 g, 30oC).
A result is a number you must mathematically manipulate to achieve. This must be copied into the
lab notebook each week.
c. Calculations - A section devoted to the mathematical manipulations you conduct. There should
be a section in the post lab where you complete the math based on your data. Including a % yield or
error calculation.
d. Analysis/Interpretation/Questions - Answer any questions posed by the lab in the data analysis
section.
e. Conclusion – Summarize the results of your experiment, and summarize the general chemical theory
addressed by the lab.
i. In this section you should describe any conclusions that you have found based on the analysis of
your data.
ii. What did you learn from this experiment, what went wrong, how could you have fixed it?
iii. Summarize the reasons for your error in complete sentences! Human error is unacceptable…it can
be prevented. “good” errors are those you can’t anticipate or adjust for (i.e. instrument error,
weather conditions, etc.).
iv. You and your lab partner will have the same results, and the same reasons for error etc. . . You
did the lab together so that is to be expected. You and your lab partner WILL NOT copy your reasons
from one another verbatim. You will come up with your own way of expressing the data,
interpretation, and conclusion.
v. A common and HORRENDOUSLY unacceptable conclusion goes something as follows: “Overall our
experiment seemed to go just fine.” You will lose points for this. No thinking here, this is about
summing up based on facts. A better conclusion would be, “The percent yield of 78% indicated a
successful precipitation of silver chloride from silver nitrate.”
Additional notebook requirements:
NO LOOSE PAGES. All lost pages or data are the students fault. If you give me your notebook and I
lose it that is my responsibility…if something falls out of that notebook and is lost, that is YOUR
responsibility.