Physics Lab Report Formats
Scott Hildreth
For many labs in our class, you’ll be asked to work with a team and create a shared lab report. To help you be successful in this effort, here are some of the most important things to consider.
Purpose of the Report: Communicate Truth
The usual stated purpose of a lab report is to communicate and discuss the results of your experiment. To this, I would add that you also want to communicate “truth” – by making and recording real measurements, read as precisely as possible but not assumed to be more precise than possible, and then drawing conclusions by analyzing actual data, with all uncertainties and errors that might arise. Making the data appear to be better than was is not good science. You want your readers to be able to quickly grasp what experiment you did, why it was important, how you did it, why, what results you obtained, and what you think the significance of those results might be.
Components of an effective Physics Lab Report:
Title Page
Abstract
Introduction
Materials, Methods,
and Procedure
Results (including answers to any specific questions asked within the lab)
Discussion
References
Appendices (including all data tables)
Title Page – includes the title of the lab, the date it was performed, the names of the group members.
Abstract – a short paragraph or two summarizing the purpose of the experiment, the key results and significance and major conclusion(s) you drew from these results.
Introduction - describes the experiment, and why it was important. What is the hypothesis that is being tested? In longer and more complex experiments, you would include the background theory and results of prior relevant research here, too.
Materials, and Methods and Procedure – the equipment you used for some experiments, you would list in the chronological order what steps you took to do the experiment. If you just followed the procedure in a laboratory manual or published experiment, you can simply say that the published procedure was followed. But you would also record here any changes you made, or variations in that procedure you chose to do, or had to do based on your equipment. In some disciplines, each of these (materials, methods, and procedure) might have separate sections. For our purposes, you can combine these.
Your goal for this part of the report is to allow anyone reading the report to duplicate your results. Good science demands that results that are to be trusted must be independently verified by other observers.
Results (including answers to questions asked within the lab) – describes what you found. (e.g. “The value of g was found to 8.9 m/s2 +/- 0.2 m/s2, or, “The thermal conductivity of copper obtained from the experiment was 386 Watts/meter-Kelvin.” ) Note that you should include in your results an estimate of the uncertainty of your calculations and experiment!
Sample calculations illustrating how you derived your results can be included here. Graphs might be needed here, but they must be clearly labeled, with slopes and intercepts included in the graph generated by Excel or other software tools.
The actual data pages from the experiment (including data written on pre-printed handout labs passed out to the class) should go in the appendix.
Discussion – This is where you impress your readers with your analysis of the data and your interpretation of your results, including a comparison with known values if appropriate, and a thorough discussion of the uncertainties in your results and why they occurred. No experiment is 100% precise, because all measurements – made by humans or electronic data gathering tools – are imprecise to some limit. Be sure to reasonably estimate what your uncertainties in measurements are (and record those in your data tables), and then account for these uncertainties in your results.
For example, if you were measuring the conductivity of a metal bar, and measured the diameter as 5.0 cm +/- 0.1 cm (in other words, to within a millimeter), your measurement is at least 1/50 = 2% uncertain. It could really have been between 4.9 cm and 5.1cm, and this uncertainty will translate to an uncertainty in your overall derived or calculated value.
When appropriate you can compare your results to those of others in the class who might have done a different experiment to isolate or refine the same quantity. But if you do this, be sure to discuss why their results were similar or different from your own.
Good lab reports look forward as well as backward, and the conclusion of your discussion (and your report) might well include predictions of how the experiment might have produced different results if done differently, with better equipment, or different procedures.
References – If you have mentioned prior work or theory in your introduction, or used outside references or sources to help you, or cited values of constants or quantities that aren’t considered to be common knowledge, you’ll include those references, properly formatted as bibliographic citations. Use your book – or better yet, a journal in the field you plan to study, to help you identify the best format to use. But be consistent in that formatting; every reference should appear with the similar arrangement of information.
Appendices – include your data and other related materials. Make sure your data tables are clear, but – for our class at least – don’t spend time recopying data. Better is just to make a copy of the pages of a lab manual.
Chemistry Department (2008, Sep 8) Lab Report Guidelines.
University of Southern