THE LABORATORY NOTEBOOK

An argument could be made that the single most important piece of equipment in the laboratory is the record book. Certainly few would disagree that performing a good experiment and then "losing" the results through failure to keep clear and organized notes is extremely frustrating. Additionally, one's powers of observation and communication of observations are sharpened by the discipline of keeping good notes. Below are offered several suggestions which have been found helpful in developing good observation and note-taking skills.

1. The student should have a bound notebook with numbered pages in which all notes, calculations, observations, and results may be recorded. These notebooks provide duplicate pages that can be easily torn out. This conveniently allows the student to submit a copy to the instructor of all lab records and to simultaneously keep a copy for his/her own use.
2. All data should be recorded immediately and directly into the notebook. The temptation to make notes on scraps of paper should be strenuously avoided. Neatness may be sacrificed by this practice, but the prevention of transcription errors more than compensates.
3. Entries should be recorded in ink. If a mistake is made, it is not erased or obliterated, but rather the mistake is crossed out, and the correct value inserted.
4. Remember that the laboratory notebook is a working document. Completeness and clarity are the major goals. We are not interested in a work of art.
5. Though there are certainly some variations in format cited by different authors, and experienced scientists usually adopt a format with which they are personally comfortable, there is general agreement on the type of information which should be included in the laboratory record book. The following elements would generally be considered appropriate:
1. student name
2. lab partner (if appropriate) and lab section
3. date
4. title of experiment
5. purpose of experiment
6. summary of the pertinent principles and synopsis of the experimental procedure
7. data and observations
8. summary
9. signature
6. The "procedure" section (5f above) should include a brief summary of the method in paragraph or outline form. It is neither necessary nor appropriate to copy the procedure verbatim from the Laboratory Manual or other source. A succinct paraphrase is good evidence that you understand the theory and lab operations. All balanced chemical reactions and formulas used in the experiment should be presented. Whenever you are following a procedure provided by this Manual or any other source, proper citation should be made. Consult The Bedford Handbook of Writers if you have questions about citation style.
7. In the "data" section (5g above) one can minimize confusion by recording data in tabular form and performing calculations as symmetrically as possible. An important part of the observation process is evaluating the uncertainty of each measurement. Data must be recorded to the proper number of significant figures and the results of all calculations made to the appropriate number of significant figures. Any graphs or plots must be made on graph paper. Observations are recorded in this section.
8. A technical paper or report written about the experiment must segregate the procedure from the records of observations (i.e., data). Such a practice leads to a much more easily followed document. Often however this is not possible in a laboratory notebook, particularly so when the experimenter is developing the procedure herself/himself. In such cases the experimenter can minimize confusion by clearly labeling each entry as procedure or resulting data and observations.
9. The "summary" or "conclusion" section (5h above) should include a clear statement of the results of the experiment. Do not simply state that the goals were accomplished. Any relevant experimental difficulties or changes in the procedure should be explained and their probable effect upon the data postulated. Any statistical evaluation of the results, such as relative standard deviation of replicates, is presented in this section. In many cases it is possible to compare the experimental result with accepted values and to evaluate what error may have led to the observed disagreement. This should be done thoughtfully.
10. In this course CHE 131, some of the experiments also include specific questions for the student. These questions should be answered in the Lab Notebook, following the Summary section. Finally, the student is reminded that anything that looks like a sentence should be a sentence.

The American Chemical Society publishes an excellent handbook for guidance in the use of the laboratory notebook, Writing the Laboratory Notebook, Howard M. Kanare, A.C.S., 1985.

An example of laboratory notes from a student experiment is presented below.