Record keeping is an essential part of the scientific process. The laboratory notebook is the primary medium for keeping these records - facilitating the recording of a range of different activities, crucial to doing effective science. First and foremost, it serves as a record of precisely what one did (both successfully and unsuccessfully) during the course of one’s experiment. It should be complete and designed to capture the goals of the experiment, the procedures/approaches used, the analysis and modeling of the experiment, the results and interpretation. By reading a lab notebook another scientist should be able to interpret what experiment was conducted, observe the data, and follow the analysis and findings. It should contain enough information such that another person could replicate the work. Furthermore, information in the notebook is essential to corroborating anything that ultimately ends up being published. Effective record keeping practice is a skill that requires substantial time to cultivate to a point where your records will be suitable for a research lab, so it’s important to start developing this skill early.
There are a variety of different types of information that researcher’s use a lab notebook to keep track of during daily lab activities. This information goes beyond simply recording parameter values and data points. The majority of the information falls under one of the four following categories:
Objective information: This consists of the parameters, settings, and data that result from measurement, alignment, or any other concrete actions taken by the researcher. This type of information is what you may commonly think of as being present in scientific records. One might describe the objective information found in the notebook as the “facts” of the experiment.
Subjective information: This usually manifests as the researcher’s interpretation or evaluation of the events in lab and commonly accompanies the objective information from the experiment. Just because this information contains the opinion of the researcher does not mean that it is “unscientific”. For example, researchers spend a great deal of time troubleshooting and redesigning their experimental apparatus in an attempt to improve their measurements – by including subjective interpretation of various measurements (e.g. “these data looked unusual” or “it seems like the alignment is bad”) the researcher can better recall their impression of prior measurements, and thus are better able to put these in the context of their current understanding of the experiment.
Analysis information: It is common for analysis to be performed on raw data throughout the entire experimental process. Often, this is done in order to directly compare experimental results to theoretical models/predictions. Examples include short calculations and plots with accompanying fits to models. The information from this kind of analysis is often recorded in the notebook alongside the experimental details about the data, which aids the reader in interpreting the results.
Planning information: This consists of future plans or directions for the research. This information can entail both short term/incremental plans (e.g. taking more data, similar to previous measurements but with slightly different parameters) as well as long term/substantial plans (e.g. complete redesigns of experimental apparatus). Researchers are constantly reflecting on and re-conceptualizing the day-to-day outcomes of their experiments; therefore it can be difficult to keep track of new ideas and experimental directions unless they are written alongside other pertinent experimental information.
Context: Understanding the context of a lab notebook entry means understanding the “what” and the “why” of each experimental decision – in other words, “what was it that I measured and why did I measure it?” It means understanding each entry in the broader picture of the entire experiment. So, when recording information in your notebook consider if you are able to understand how what you’re writing pertains to the experiment as a whole. If you are simply writing down the numbers for each parameter and listing the different data that you’ve recorded without explaining the reasoning behind the measurements, it is likely you will be unable to make sense of what you’ve written later on.
Audience: You are the primary audience of your notebook, but authentic research is done collaboratively, therefore the lab records of an experiment must be available to all the researchers involved. This may include peers in the same research group, one’s advisor, or researchers from collaborating research groups. Thus, when writing in your notebook try to imagine how your writing may be interpreted by others. Keep in mind what things you infer or assume, without writing down, and ask yourself whether or not others may be able to make sense of the context of your entry without this information. In the case of your lab class, your audience will also likely include your lab partner and your instructor.
Timescale: You will find that you may need to reference various pieces of information recorded in your notebook in a week, a month, or in the case of authentic research potentially more than a year from when it was recorded. Of the information you write down, you will never know what you will need and when you will need it, but through experience you will find that some of the information maybe be of more short term importance (e.g. equipment parameters that will be updated in the subsequent few days) whereas other information you may keep coming back to over the course of weeks or months (e.g. a commonly reproduced alignment procedure). It is important to be mindful of this when writing each entry – it is good practice to ask yourself “When might I need this?” whenever writing down new information. The farther in the future that may be, the more detail you should include.
Time investment: The process of keeping lab records is a fine balance between writing enough detail so that your records will be useful in the future and doing so in a time efficient way that does not slow the progress of your experiment. Record keeping is a time intensive part of the experimental process – many researchers express that they feel they should be taking more time to write additional information in the lab records that they keep. Very few of them feel that they spend too much time adding detail to these records. Do not look at record keeping as an afterthought to the actual experimental process, but rather as an integral part that will require substantial amounts of your lab time to get right.
Your lab notebook should tell a story of what you did and what you were thinking as you did it. It is kind of like a scientific diary, complete with sentences, diagrams, graphs, calculations, and raw data. You should write in it while you work in the lab, and then add more later as you carry out your analysis. The most important test of a good lab notebook is, “Years from now, could someone else replicate what I did using only my current equipment and my notebook and as a guide?” You should write in your notebook with this test in mind.
The recommended method for keeping a lab notebook and plotting data is Microsoft OneNote and Mathematica. If you prefer another method of writing up or plotting this is acceptable, as long as it produces a clear, legible final PDF or PDF scan that conforms to the ideas below. If you use a paper notebook, please acquire a spiral-bound quad-ruled notebook. You will be uploading a PDF of your lab notebook (either exported to PDF if using a digital notebook or scanned and saved to PDF if using a paper notebook) to Canvas each week and these will be reviewed and graded by your instructor. Your score on each lab will depend, in part, on how closely your notebook matches these guidelines and how easy it is to follow the “story” of your lab work.
Here we present some examples of notebook records taken from a physics research lab here at CU Boulder. The various entries are recorded by several different researchers who are working collaboratively on the project. You will notice that each researcher has a different style and format to their entry, but much of the same information and thought process can be seen in each entry. These excerpts are meant as examples of authentic scientific record keeping and do not represent a definitive illustration for how you should maintain your records.