The Lab Notebook or Journal
What is a lab notebook?
A lab notebook is a detailed record of experiments. It includes both disasters and successes, all observed changes, as well as unusual occurrences (color, odor, dropped sample, very humid day, etc.). Everything surrounding an experiment should be written down in a lab notebook. Ink must be used, not pencil. Mistakes must NOT be erased, but are crossed out with a single line through them.
A lab notebook contains permanently-bound pages, which are sequentially-numbered. Some notebooks contain carbon paper so that copies can be made.
Why keep a lab notebook?
A lab notebook is kept to help the scientist remember the experiments that were performed, the conditions, the reasons for the experiments, and the successes and failures. It is also used to document the dates of discoveries (for patent applications). Lab notebooks are useful to others who may want to reproduce key experiments. Detailed record-keeping can also help in the interpretation of experimental results (e.g. one of 5 replicate samples that is very different than the rest may have been dropped on the floor–the dropped sample must be marked and the dropping event recorded).
What is the format of the lab notebook and what should it contain?
#1-6 and #12 should be written down in the Lab Notebook before beginning the experiment.
#7-12 are written down during and after the experiment.
1. Table of Contents
The first 2 or 3 pages should be left blank initially, so that a Table of Contents can be developed as experimental records are added to the Notebook. The Table of Contents should include the Date of the experiment, the title and the page numbers of the experiment. Usually, one does not know how many pages will be used for a given experiment until it is over. Thus, during an experiment, the Table of Contents will have a starting page number. The final page number will be included after the experiment and its analysis are completed.
2. Short Title
A short, descriptive title is useful in quickly identifying and locating specific experiments and in triggering one’s memory.
3. Dates
Every time an entry into the Notebook is made on a new day, that date should be entered. Some experiments may take several days to complete.
4. Purpose
Write down why an experiment was performed. This will help the scientist keep track of her/his “train-of-thought” processes. Usually each experiment is designed to answer a question or test a hypothesis.
5. Materials and Equipment
In order to reproduce an experiment, one needs to know the sources (vendors such as Aldrich Chemical Co., Hewlet Packard, etc.), condition, and characteristics (purity, instrumental design, form, etc.) of the materials and equipment that are used. Thus, this is essential information that must be entered into the Lab Notebook.
6. Original Procedure
The procedure consists of all of the steps that will be involved in the experiment. The more detailed this section, the more reproducible the experiment. Sometimes this is just an outline of a procedure published in the literature. Sometimes it is a brand new procedure that the scientist has planned to carry out.
7. Observations
Once even the preparation for the experiment is underway, all observations must be recorded. These include time of day, solutions that are prepared, any checks that are made on equipment that insure that it is functioning properly, any measurements, mistakes, changes in colors or form or temperature, etc. This section also includes the ACTUAL PROCEDURE that was used. Sometimes a scientist changes the original procedure (outlined in #6 above) while an experiment is in progress. These changes must be recorded.
8. Calculations
Whenever any calculations are performed, they must be recorded into the Lab Notebook. This makes it easy for others to understand how you made your determinations. It also makes it easy for you to track down errors after an experiment is over.
9. Discussion
What makes a scientist different than a copy machine is that the scientist does not merely copy down the measurements and results, but she/he also interprets them. Consequently, there should be a section in each section of the Lab Notebook for each experiment for a discussion of the meaning of the results. This section can be extremely valuable. It is important that you try to interpret the results as soon as possible during or after the experiment, while the data are fresh in your mind.
10. Conclusions
The conclusions section is a summary of the results. It condenses the Discussion section to a paragraph or so. This section makes it easy to review old experiments.
11. Future Experiments
Always enter improvements to old experiments or new experiments that will answer new questions that have arisen. This section is helpful in following the train-of-thought of the scientist and records new ideas that otherwise might be forgotten once the experiment is over.
12. References
Any sources of information (books, articles in periodicals, communications with others, etc.) that were consulted before designing the experiment or interpreting the results need to be included.