Doyle Online Writing Lab

Laboratory Notebooks

Scientific knowledge is disseminated via the published research article, and the accuracy and integrity of such presentation depends on reliable record keeping. The skill of writing the Laboratory Notebook is a vital part of industrial and academic research and is required by law to establish intellectual and patent rights. The task of writing a laboratory report (or your senior thesis!) can be immeasurably enhanced by good record keeping.

A laboratory notebook is the written record of everything that was done (good and bad) and all relevant plans, observations, notations, interpretations, and conclusions. Resist the temptation to keep an overly tidy notebook that has been whitewashed of mistakes; it is supposed to be a diary of work in progress. You can keep a second notebook that summarizes the key results and gives the big picture. The laboratory notebook is the ultimate source of data and other information necessary for putting it into a cohesive picture, and for the hindsight required for effective trouble-shooting of future procedures.

1. Organizing Your Notebook

  • Laboratory notebooks should be hardback bound books.
  • Writing must be legible and in durable ink.
  • Title Page. Use the first page for your name, address (although a lab notebook should NEVER leave the research lab, in a teaching lab you will carry this with you), and its purpose - Introductory Biology.
  • Table of Contents. Save two pages to list the experiments and page numbers.
  • Number the pages. Do it when the notebook is new.


  • when the work was done (The date, including the year, should be on every page.)
  • where it was done (This is especially important for field work.)
  • who did the work (Recording your lab partners' names will be helpful in contacting them later.)
  • what was done and how it was done (step by step) so that anyone could repeat the experiment.
  • why it was done

2. The Experimental Introduction

  • Title the experiment.
  • Put the experimental title on any pages attached to your notebook, in case they become unattached.
  • Write a short statement of the problem or task.

3. The Experimental Plan

  • Write an outline of what you plan to do and where you got the information necessary for your design.
  • You can attach instructions from the lab handout and make a note of what has been attached.
  • Make tables with labeled columns and rows for recording data and observations.
  • Calculate recipes for solutions to be prepared including concentrations, volumes, and pH.
  • Safety! Note how to deal with safety issues withchemicals or practices that may be dangerous.

4. The Experimental Execution

  • This is different from the plan.
  • Tell what you actually did, including any mistakes, missed steps, pipetting errors etc.
    Identify precisely what equipment was used.
  • Describe/diagram settings, adjustments or calibration.
  • If the protocol said, "wait 15-25 min", be more specific: "start wait 3:56am" and "stop wait 4:17am".
  • Record chemical lot# and expiration dates.
  • If in doubt, write it down. You never know what may be a relevant factor in an experiment.
  • Record what parts of the experiment you do and what parts someone else does.

5. Observations and Data

  • Record honestly. Faking data is in violation of the Honor Principle.
  • Record as you go along, in the notebook, in ink, immediately.
  • Do not trust to memory, even for a minute.
  • Do not use odd scraps of paper or the edge of your lab coat to record data or make calculations. Only if your data is in a notebook will it be available for future analysis.
  • Only if the calculations are in your notebook will you later be able to detect errors.
  • The raw data is precious - treat it with the care you'd bestow on a family heirloom.
  • The data must be recorded as completely as possible. Use and define meaningful abbreviations.
  • Take care with numbers. Use the leading zero as in 0.15 rather than .15.
  • Always write the units when units exist.
  • Never erase or overwrite, cross out erroneous material with a single line.
  • Never tear out pages.
  • If errors are found later, or notes are added at a future date, indicate the date of the new annotation.
  • When data are recorded directly into a computer, note the name and location of the computer file.
  • Give computer files informative names.

6. Graphs

  • The axes must be labeled with what they are and units in parentheses. Time (min)
    Figure legends should start with a short title and then describe how the data were obtained.
  • Attach graphs produced on a computer, and note the name and location of the computer file.
  • If supporting records (photographs, printouts, etc.) cannot be attached to the notebook, keep them well organized, properly labeled, and readily retrievable. State where they are in your notebook.

7. Discussion and Conclusion

  • Write any calculations out clearly, showing all the steps and units.
  • Interpret your results in relation to your hypothesis.
  • If results were not as expected, how were they different? Can you continue the experiment and why?
  • State your conclusions clearly.
  • Include suggestions for improvement in experimental design.
  • Describe what to do next.
  • Record any ideas you have- if you don't write them down, no one will know you had them.