The Laboratory Journal

An essential part of all scientific experiments is a carefully kept record of everything that was done in the laboratory. It should be written with blue or black pens (NOT pencils or red pens) and should include the following:

• A prelab writeup, a 1/2 to 1 page summary of what you will do in that week’s experiment (and why) and how you will accomplish those tasks
• The date and lab partners’ names
• Brief descriptions of what you do for each part of the experiment along with sketches of the apparatus
• Tables of the data as they are taken
• Notes on difficulties in taking data and how you circumvented these difficulties
• Preliminary plots of the data, properly labeled and with correct units
• Preliminary data analysis and conclusions (Include proper significant figures, random error calculations and systematic error estimates, etc. Do things make sense? How do the results compare with theory?)
• Observations of unexpected occurrences and effects
• A pledge that the work is yours (and your partner’s) and that it has not been altered since leaving the lab. No pledge, no credit.

Write down all these things as you go along. All mistakes must be clearly crossed out; they should not be erased or whited out. Both the original and the new recordings must be visible. Each lab partner must turn in a copy of the journal along with the lab report. No changes or additions are to be made to the journal at home.

The Laboratory Report

In addition to the lab journal, you are to hand in a formal, self-contained report about the experiment that you have done. In this report, you are expected to present, in proper English, the motivation for the experiment, the results, and the conclusions drawn from them. The experiment should be described in enough detail so that someone knowledgeable in the field can understand what has been done and why. The report should include the following:

• A cover page, including the lab title, your name, your partner’s name, the date and time of the lab, the TA's name, and the lab section number.
• The motivation of the experiment
• A summary of the results and data analysis including standard deviations and error estimates. Graphs and tables should be labeled (e.g. Fig. 1 and Table 1) and attached in the back.
• Answers to the questions in the lab manual and any the lab instructor added.
• An analysis and interpretation of the results and a conclusion. For example, do the results match the theory within the experimental error (see Appendix D); if not, why not? Did the experiment push the limits of the approximations made in the theory? Is there another possible source of systematic error? What was learned from the lab?
• A pledge that the report is your own independent work. No pledge, no points.

The text of the report is limited to 2½ pages. You may have as many tables, graphs and figures as you wish, but remember that these should include summary information only (i.e. average values and standard deviations). Margins must be at least one inch, text must be double-spaced, and the font/type face size must be no smaller than 12 pt Times (New Roman). If you decide to write out your report by hand, it must be neat and legible to your lab instructor.

The report (with journal attached) is to be handed in at the beginning of the next lab. They will be graded and returned at the following lab. The only exception is the final experiment which you will write up during the lab and hand in at the end of the period.

Grading Policy

Each complete lab report will be assessed on a ten point scale, up to five points for the journal and five points for the report. The assessment will be based on the quality and completeness of your performance in the laboratory as evidenced in your journal and report sections according to the requirements discussed above.

Your final grade will be determined by taking the average of all of your lab grades. Grades will be assigned on a curve based on your lab instructor’s students only. If your grade is on a borderline, your lab instructor may adjust your grade according to your lab performance.