The Lab Notebook

The keeping of lab records by students in the Second Year Lab is part of your training for your later scientific life. We thus expect that your notebook will resemble that of a professional scientist. The following is an attempt to clarify our lab notebook expectations.

    WHAT THE NOTEBOOK IS FOR

The notebook provides both a structure for recording your experimental work and a record of that work. Thus, records and calculations made during the experiment are systematized by being written in the notebook. And thus, scientific and legal records are kept there for later use. A "typical" scenario is a data-run on a machine on which a group of 5 researchers work round-the-clock for two weeks. During that time, machine and experimental problems arise and are solved (or not solved), experimental details are changed, both according to the original plan, but also to answer new questions posed by the data obtained, and data is accumulated, recorded and analyzed. At a later time (sometimes as much as 5 years later) the data from this run is combined with data from other runs, final calculations are made, and a paper is submitted for publication. Months later, the paper gets returned by the journal's referee with comments requesting revisions. The original data and calculations are then used as a basis for revisions. The revised paper then gets published. Finally, ten years later, there is a patent dispute based on findings from the experiment. In the court proceedings, the original lab notes are used as evidence.

    WHEN ENTRIES ARE MADE IN THE NOTEBOOK

Whenever you do any work on an experiment, you should be making entries in the notebook. Your notebook is a diary, and so entries are made in chronological order. These entries should all be dated.  Notebook entries start with jottings on your preliminary background reading and investigation, progress through records of your experimental set-up, include data (which is both numbers and narrative) and calculations, and end in evaluations and conclusions. All these entries must be made simultaneously with the actions they describe. Thus, indications of apparatus  must be written at the time are observed, not two weeks later.

    WHAT SHOULD BE ENTERED IN YOUR LAB NOTEBOOK

• Dates (and times) liberally spread throughout the data/figures/narratives.
• Sketches of important details of the used apparatus. In most cases, schematic representations are preferable to pictorial detail. This is particularly relevant to electrical circuits.
• Data ­ numbers, comments and descriptions ­ systematically entered (in tabular form where possible). All the data should be there, including the data that failed (with annotation of why it failed). In particular, all anomalies and surprises and your reactions to them should be included. Note that error estimates are part of your data.
• Preliminary calculations based on the data, preferably also in tabular form, and preferably as extended columns in the data table. Do not include detailed arithmetic, although algebraic equations, explaining how each calculated column in the table was found, are useful.
• Preliminary graphs based on the preliminary calculations and inserted with the data. These graphs should be well labeled and dated and should be liberally annotated with remarks about features of the graph as related to oddities in the data-gathering process.
  • NOTE: These preliminary calculations and graphs should always be made while the data is being accumulated. In the "typical" data-run scenario, the preliminary graphing is essential. (Picture two round-the-clock weeks of work with no preliminary graphing. A month later, it is discovered that one data point does not make sense or that more detail is needed around part of the data. By a month later, it is very difficult to start-up the whole run again.)
• Data sheets produced by your equipment (chart recorder sheets etc.). Such sheets should be dated and cross-referenced to the writing in your book and annotated re notable occurrences. Loose sheets should be taped into the book. In the event that data are saved in computer files, complete descriptions of filenames and locations should be included.
• Final, more elaborate, calculations and graphs, and descriptions of the methodology and strategies used in the calculations.
• Final comments, conclusions, thoughts about the experiment.

  • NOTE: Your notebook is not a formal report ­ it is not a beauty show. You will write just one report in the "formal" form per semester.

  LENGTH, ORGANIZATION AND WORK OUT OF THE LAB

   

• Your notebook is your complete record and thus the entry for each experiment must be long enough to allow you to fully reconstruct the experiment from the written record. However, a 50 page entry for a second year experiment is a waste of paper and a waste of your time. This implies that organization is essential to work in the lab. It is important for you to learn to plan what you will do and write before you start doing and writing in the lab. It is also important that you organize your work so that no more than one hour is spent working on your notebook after you have completed your experimental (and writing) work in the lab. Almost all of the entries in your lab notebook must be made in the lab. And note: lab notebook entries should be in pen; pencil disappears with time and is too changeable.