Laboratory Notebook

Good record keeping is important when doing experimental work, and you will be required to keep a laboratory notebook for your experimental work in this course. Even though you may work with a partner or in a small group, you will need to keep your own notebook.

On days when experiments are scheduled, you are expected to come to laboratory having already read the background information on the experiment. From your background reading, you should be able to state the objective of each experiment. Include this objective in your notebook. Write terse procedural instructions in your notebook BEFORE coming to lab. And work out any prelaboratory exercises directly in your notebook. Plan appropriate data collection tables and draw them out ahead of time.

As you carry out the lab, your notebook will serve as an experimental diary, so be sure to record what you are doing and thinking during the experiment. One way to differentiate between the prelaboratory work and the running account you keep during the experiment is to divide the page in half vertically. Concentrate the prelaboratory work onto the left hand side of the page, and any modifications to the procedure as well as the data collection and notes can then be made on the right hand side of the page.

After each experiment, you should write a reflective summary to help you organize and interpret your findings. These reflective summaries should also be included in your notebook.

Keep the following in mind as you prepare your notebook.

1. Basically, a lab notebook should:
   • Say what you did—write out the procedure in enough detail so someone else can repeat your work.
   • Note any deviations to the procedure.
   • Say what happened—Experimental observations such as changes in state or color, evolving gas, or any other interesting observations should be noted in your account.
   • Be understandable to someone else—Your TA, for example, or a lab partner should be able to read and follow your work and your thinking.
2. Specific elements of a good lab notebook:
   • The notebook is a diary: a faithful record of what you were doing and thinking at the same time.
   • Notations are in ink and taken down as things happened—not re-copied!
   • Mistakes are neatly crossed out with a single line—not obliterated or whited-out.
   • Each entry should be dated.
   • Quantities and results of calculations are identified, carrying units and perhaps uncertainties. Final results are reported with appropriate significant figures, units, and uncertainty/standard deviations.
   • The notebook is organized, neat, and legible-it needn’t be a work of art!
   • Graphs, spectra, etc. are affixed in the notebook.
3. Elements of a good experimental account in a lab notebook: In general, your experimental work reflects real-time THINKING and DOING. If an experiment takes several days, each day of work should be logged in the notebook, and should reflect experimental work, calculations, and a reflective summary of what you did. Each daily entry should have the following components.
   • Objective: Concise statement of the experimental objectives.
   • Method: Recounted in sufficient detail to repeat experiments.
     • It is acceptable to paste the “Methods” section of the manual in your notebook as an initial reference. If you choose to do this, be sure to document any changes in the procedure that deviated from the proposed plan.
   • Running Account
     • Raw data (tabular form if possible/appropriate).
     • Observations, to include observations of color change, precipitation, gas evolution, or simply cool stuff you didn’t expect.
   • Calculations (and error analysis if appropriate)
     • Clearly stated equations used (assumptions and theories, if appropriate).
     • Perform calculations needed to transform raw data into final results—use units!
     • Uncertainties for raw data based on reproducibility and/or accuracy.
     • Uncertainties correctly propagated to final results.
     • Explicitly state major contributions to experimental uncertainty.
   • Results/Reflective Summary/Discussion (needn’t be long)
     • Comparison of results to previous literature values (if appropriate).
     • Examination of data for trends, systematic error.
     • Suggestions for improvements and future experiments.
     • Summarize important findings and their interpretations.

Below are example notebook pages, provided for your reference.