Lab Notebook Information

How to Keep a Good Lab Notebook

The lab notebook is the scientist’s most important tool. It is used to record the information required for any person with at least your level of technical understanding to reproduce your work exactly. Details to record include your procedure, observations, and data. The lab notebook must be neat, organized and a complete record of what you do in the lab.

The notebook should be bound, never loose-leaf, and the pages numbered consecutively. Purchase a “Composition Book” for this purpose. They can be had for about $1 in office supply stores. Write in ink, never with a pencil. Neatness is essential.

Reserve the first two full sheets of paper in the notebook for a Table of Contents. Write “Table of Contents” at the top of the first page. For each activity or lab enter a number followed by the title of the activity or lab and the date. Follow this with a page number.

Follow the following format exactly when writing in your lab notebook. Start a new page for each activity or lab. Enter a page number at the bottom of each page that you use, starting with page 1. Set up section headings as described below and write the required content in each section.


Write your name and your partner’s name(s).

Title and Purpose

In this section give your work a title and a brief description of what it is about. If you are testing a scientific idea then state the hypothesis to be tested in the lab as clearly as you can.


In this section write brief notes about what actions you take. Do not copy a lab hand-out word for word. Instead, summarize and stick to only the essential details. Also, give a reason for the actions you take. A set of related actions may all have a single purpose. State this purpose and put it in the context of the big picture: what is this activity about?


When you do anything in the lab or perform any home experiment you must write down what you observe. Do use your eyes. To the extent that it is safe to do so, use the sense of touch. Do not take huge lungfulls of chemicals in the lab but do note any odors that you smell. What do you hear? Use descriptive but not flowery language. The purpose here is not to impress with your vocabulary and literary skill. Instead, think of yourself as Sherlock Holmes. Every detail you notice may be a clue to solving a mystery.

Your observations should include text but also drawings, diagrams, and graphs as appropriate.


In this section record questions you have about the work you are doing. Did something weird happen? Do you wonder why you’re taking certain steps written in the lab hand-out? Did your work make you think of something else you’re curious about?


Make data tables that are neat, well-planned and complete. Leave space to fill them. Do not forget units. Always write down all of the available digits from whatever measuring tool you use. You will have to think ahead and understand the purpose of your actions in the lab in order to properly plan your data table.

Under each data table write a few sentences describing what the data show or giving the purpose for which the data were collected.


Prior to writing a lab report write preliminary answers to questions from your lab handout in your lab notebook. These are designed to guide your thinking and help you to understand your work. For any statements you make about the outcome of your lab work be sure to give evidence in the form of observations and measurements.

Consider possible sources of error. Never use the phrase ‘human error’. Give specific, physical causes which may have led to your measurement being higher or lower than expected. For example, if your measured mass of a powder was too low you could give as a source of error the fact that you observed some of the powder fall onto the counter-top before you could weigh it.


How did the lab turn out? What went well? What didn”t work? Was the purpose of the lab fulfilled? Evaluate the lab’s hypothesis (if there was one).

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Rules for Writing in your Lab Notebook

Keep your records according to the guidelines below.

  1. Give dates of all work—begin each session of lab work by entering the date in the notebook. If you think that the timing of steps may be important, enter the time you begin each important operation.
  2. It is not acceptable to keep notes—any notes of lab actions, observations, and data—on scrap paper. Your notebook is your scrap paper.
  3. This is the most important thing for a good notebook: it must contain enough detail that someone unfamiliar with the experiment can perform it by following your notes, using your observations to help them see if all is going well.
  4. You should develop the habit of recording your notes at regular intervals throughout your work. It is not acceptable to work for the whole period and then try to summarize your work—too much detail is lost. Of course, your writing must be legible.
  5. If you are working in a group, write down who did what. Each member of a lab group must take their own notes. Do not leave all recording duty to one person, expecting to copy it down later. You may notice something important that no one else notices. Also, you may never get a chance to copy down the information before the lab report is due!
  6. Avoid leaving any blank pages. Try to place diagrams and calculations near the text that describes them. Graphs or tables printed by computer should be neatly taped to the page and positioned so that they can be easily read from the bottom of the page or from the right hand edge. All tables and graphs should have titles that explain what they are.
  7. Writing the report will be a matter of organizing entries taken from your notebook, if your notebook is neat and includes the necessary information.
  8. If you are working on a project I assigned for you to do at home, keep notes on it in your lab notebook.
  9. Write using a pen with permanent ink; never use a pencil. If you make an error, cross it out with a single stroke (like this). Do not erase or black out your mistakes.
  10. Neatness, organization, spelling and grammar count! Your lab notebook must clearly record everything someone would need to know to reproduce your work. All data and information in the lab notebook must be presented with logical organization. Everything you write should be in grammatically correct, complete English sentences.

Lab Notebook Grading

You will receive two different types of grades for your lab notebook. All grades will be worth 30 points as compared to 50 points for a short report or 100 points for a formal lab report.

Spot Checks

I will walk around the room and glance at an entry in your lab notebook. I will give a comment or two and a grade as follows:

  1. 30/30 (100%) will be given for a lab notebook entry that includes all headings, follows the format exactly, and contains appropriate content.
  2. 22.5/30 (75%) will be given for a lab notebook entry that does not follow the format and or which is missing important content.
  3. 15/30 (50%) will be given for a lab notebook entry that is present but which does not meet the standard. Perhaps it is sloppy or is missing important parts of the format or content.
  4. 0/30 (0%) will be given for a missing lab notebook entry.
Big Picture

I will check to see whether you have all of your lab assignments written up in your Table of Contents. I will then choose three random entries to look at with you. Grades will be assigned as above, where 100% will be given only if all entries are present, correctly formatted, and contain appropriate content.

This page was inspired in part by
information about lab notebooks
from the faculty at the University of Southern Maine.
USM Chemistry Homepage
Last updated: Aug 27, 2015       Home