How to Write a Logbook for a Science Project

In industrial and academic research settings, laboratory notebooks constitute legal documents; they are official records of who accomplished what and when it was accomplished. Just as important, a well-kept logbook prevents a scientist from needlessly reproducing experiments and, in the process, wasting the scientist’s time and his employer’s materials and resources. Keeping a laboratory notebook or logbook is one of the most critical skills for young scientists to learn and is an integral part of a scientist's training.

Obtain a suitable notebook to serve as the logbook. Ideally, it should feature a sewn binding (not loose leaf, where pages can be removed and inserted). Using a permanent ink pen, number the pages in the top right corner.

Write in the logbook using permanent pen only, and do not use correction fluid. Any time a mistake is made, draw a single line through the error and then continue as though the error never happened. Do not attempt to black out the error. This makes a mess of the notebook and may cause someone else examining the notebook to wonder if the experimenter was attempting to hide information.

Begin the logbook by recording the date at the top of the page and writing a short description of the experiment to be undertaken, including the objective. That is, address why the experiment is being conducted and what information the experimenter hopes to obtain at the experiment’s conclusion. An example might be, “Determine the amount of dissolved solids in seawater by evaporating a sample to dryness and weighing the residue.”

Record every step undertaken during the course of the experiment immediately after it has been performed. As such, this information should be recorded in the past tense. Do not feel compelled to write in the first person (do not use the word “I” as the subject of sentences). An example would be, “Weighed an empty 250-mL beaker and then placed 50 mL of seawater in the beaker.” The guiding principle is to provide sufficient detail such that someone else could reproduce the experiment and achieve the same results.

Record any and all measured values to the maximum number of digits provided by the equipment. If a balance, for example, indicates a mass of 56.7890 grams, then record all 6 numbers, including the last zero. Numbers can be rounded later during calculations, but numbers that were not recorded cannot be recovered without repeating the experiment in its entirety.

Show all calculations necessary to process the data, even the trivial calculations, where two numbers are simply added or subtracted. This will greatly enhance the speed with which mathematical errors can be tracked down and corrected.

At the experiment's conclusion, write a brief statement concerning your (the experimenter’s) reflections on the results. Were the results reasonable? Were any problems encountered that might have affected the results? If the experiment is to be repeated, what should be done differently next time?