How do I keep a laboratory notebook?
Your laboratory notebook is the primary repository for the data you collect in your laboratory courses. It is therefore important that you adhere to proper note-keeping standards. All entries in your laboratory notebook must be clear and complete; it should contain sufficient information that your teams and your TA can read and understand without any difficulty. A well-maintained notebook will help you prepare your reports, so use it to your advantage.
1. The laboratory notebook should be a readable document, not merely a logbook in which numbers are recorded. Your records must contain everything necessary for someone else to read and fully understand the experiment: an overview of the experiment, a brief description of the apparatus, all your collected data, an outline of the data analysis (and principal findings), and major conclusions. Your notebooks should be up-to-date at all times: always write down what you are doing or thinking AT THAT TIME, not later. “Pasted-in” items should be limited to data traces acquired by computer or graphs and figures produced by spreadsheets. You should NOT paste in sections of text.
2. Record your analysis in your notebook. For example, if you are fitting your data to a theoretical model, your notebook should contain the equations describing the model (do not forget to cite the source from which the equation was taken), the parameters obtained from the fit, and a graph showing the fit superimposed on the data. Although the data fitting itself is done on a spreadsheet, it is essential that you record the method of analysis and the principal findings in your laboratory notebook as they are obtained.
3. Always try to quantify errors at the time of measurement. For your error analysis, you will need to identify possible sources or error, as well as estimate their magnitudes.
4. Record your visual observations. What color is the solution? Is your mixture boiling at a specific temperature? Also record changes in what you observe.
5. Properly annotate errors. For example, suppose you realize that the calculations on page 17 of your laboratory notebook (which was done earlier during the experiment) are incorrect and you are currently up to page 25. You should first draw a single line through the erroneous section on p. 17, and add a note in the margin that these calculations are incorrect and that the correct version is on p. 25. You should then date and initial the note.
6. Table of Contents. Reserve the first two pages of your laboratory notebook for a table of contents. The purpose of the table of contents is to help a reader find the page he or she is looking for. Consequently, the entries in the table should be sufficiently descriptive and numerous that a reader can easily identify the proper section and go directly to the point of interest. A subheader such as “Data Analysis” under “Experiment 1” does not provide sufficient information. Instead, try “Data Analysis: Estimating Stage Efficiencies.”
For more information on laboratory note-recording, refer to Writing the Laboratory Notebook by Howard M. Kanare (Washington DC: America Chemical Society, 1985). The most relevant sections are pp. 1-8, 14-16, 40-41, 44-45, 53-79, 81-93, and 126-127.