Your laboratory notebook is the original, authentic, permanent, legal record of your laboratory experience. The guiding principle for composing a laboratory notebook is that the document should allow another individual with your level of experience to replicate your experiment or investigation. In this course, you must use an electronic lab notebook in the form of a Google Document (template provided).
For any laboratory activity, notebook entries are made in three distinct phases. Pre-lab entries describe the objective and plan for an experiment, and they should simplify the task of recording data while the experiment is in progress. In-lab entries should be a running account of the experiment as it is performed. Post-lab entries are written after the experiment is complete and are meant to interpret and summarize the collected data. An annotated example lab notebook entry may help you to visualize a properly completed lab notebook.
1. Entries should be made directly in the notebook as the experiment is performed. Information should never be recorded on separate pieces of paper and then transcribed into the notebook.
2. Recognize that the notebook is a working document. It is not a piece of finished artwork. All laboratory notebooks contain mistakes and notes of explanation or clarification.
3. Mistakes should be corrected but never removed. A single line should be used to strike through any error. Changes in primary data (e.g., the mass of a reactant) are usually initialed and accompanied by a note of explanation.
General Guidelines for Pre-lab Entries
1. The title should convey the primary task performed during the experiment.
2. Each page should be dated as entries are made.
3. Lab Partner. If you are working in a group, the name(s) of your lab partner(s) should be recorded.
4. Purpose statement. Briefly summarize the scientific objective(s) of the experiment.
5. Background. Appropriate background information varies widely with the type of experiment. In general, you should include any information necessary for someone with your expertise to understand and accomplish the lab. Typical background information includes a chemical equation, important data for the materials used, and any relevant calculations (i.e., theoretical yield). It might also include a description of the technique or instrument employed during the experiment or the mechanism of a reaction. Safety precautions should be clearly noted in the background section. The three most common forms of background information in this course are:
• Reagent Table: List any chemicals used in the experiment with relevant physical and safety data (e.g., molecular weights, quantities used, densities, hazards, precautions, etc.).
• Reaction Equation: If the experimental objective involves a chemical transformation, a corresponding chemical equation should be provided. The equation should illustrate the reactants, reagents, conditions and products.
• Reaction Data Table: For substances used in a chemical reaction, include a table that provides information about stoichiometric ratios. The sample laboratory notebook provides an example of a typical reagent table.
6. Procedure Outline. Outline the intended procedure in enough detail for you to follow easily when you enter the lab. You may use a list or flow chart format in this section. The pages in your notebook are divided into columns. You may find it helpful to record your procedure in one column, leaving the adjacent space free to record any procedural alterations and data gathered. It is often helpful to include pre-designed data tables to simplify the task of recording data while completing the experiment.
General Guidelines for In-lab Entries
1. Fully describe your actions during the lab. If you have a well-written procedure outline, you simply need to record any planned or unplanned deviations from the protocol as you carry out the lab.
2. As you carry out the procedure, you should record the raw data you collect directly into your notebook. This includes any measurements taken and the actual quantities of materials used, which will inevitably vary somewhat from the planned quantity in the procedure.
3. Numbers are not the only type of data you gather in the lab. It is important to record what you observe (e.g., precipitates, color changes, bubbles, heat generated, smells, etc.) during the course of the experiment.
General Guidelines for Post-lab Entries
Calculations/Analysis. After the experiment is complete and all the data is gathered, you must examine it to determine its meaning. Raw data often must be manipulated in some way. Record your calculations or analysis of the data so that someone else could follow you reasoning and confirm your results. The example lab notebook illustrates the types of information that should be included in this section.