A sample calculation showing every step used to treat the raw data should be presented. This part may be handwritten but must be neat. It is neither necessary nor desirable to show repeated examples of the same basic calculation. Describe the purpose of each step and indicate clearly the source of every quantity which you use in the calculation. Appropriate units should be used throughout the calculation.
Error analysis Make a quantitative estimate of the quality of the results.
For every measurement include an experimental uncertainty. The best time to determine the uncertainties is while you are doing the experiment. In many cases it will be up to you to estimate an appropriate uncertainty. The estimate will be based on the reproducibility of the data if more than one reading was made. In cases where only one reading is made you must make an educated guess which should, of course, include a justification.