This entry help you to prepare laboratory reports for all general science and engineering at PUC-EPS-UA. It describes the structure of a good laboratory report, outlines the different sections of the report, and explains the need for each of them. It also introduces some standard conventions and rules for writing reports of professional quality.
Laboratory reports will be graded not only for technical content but also for writing and style. The quality of your written report will strongly affect your grade for the course. Students are required to follow the general rules in this entry and the specific format instructions given to them by their laboratory instructor.
General Outline of a Laboratory Report
Scientific writing is just as important as scientific investigation or experimenting. Although the major part of scientific investigation takes place in the laboratory–connecting equipment together, repairing, obtaining supplies and samples, checking each apparatus for consistency, calibration, and finally data collection by running the experiment—a great deal of time is spent to present the results in a concise, objective, critical and conclusive format called laboratory report (similar to research paper). Therefore, a well-organized laboratory report is much more effective and influential than one without a structure. There is no short list of instructions for writing a good laboratory report. You may have only one chance to influence your reader. While ineffective writing can turn off the readers, a well-written laboratory report can have impacts on your reputation, chance of employment or promotion. You may also draw the attention of the scientific community to your work and retain them as your readers.
Sections of a laboratory report:
A laboratory report usually have several sections identified by titles. A typical report would include such sections as TITLE, INTRODUCTION, PROCEDURE, RESULTS, and DISCUSSION/CONCLUSION. If you are using a computer to type your work, section headings should be in boldface.
The title can usually draw attention of the reader to your work. It should clearly represent the work presented. If the purpose of the experiment is to measure the gravitational acceleration of the earth using pendulum as the experimental apparatus, the title should be like “ Measurement of the Gravitational Acceleration Using Simple Pendulum”. Avoid “The” as the first word in the title for it will lead to misleading searches when one uses the database.
State the purpose of the experiment in general terms. For example, “ It is possible to measure the gravitational acceleration using the oscillations of a simple pendulum.”
Review the existing information or the theory. Reader will look for some reminder of the basic information relating to this particular area. This can be done by giving him/her a brief summary of the existing state of knowledge. We can also include a summary of earlier work with proper references.
Supply a paragraph or two about how the basic information, such as an equation representing the behavior of a model (theory), can be used to make measurements.
Indicate what parameter or properties of the system you are measuring. Usually you change a parameter of the system (such as changing the temperature, independent variable), and measure its effect (such as the length of a metal rod, dependent variable).
Specify such measurement details as the type of standard or instrument used to make the measurement (for example, meter stick or vernier calliper, etc). Give the instrument uncertainties. For example, if we are using a meter stick, we can say, “ the length of the rod is measured using a laboratory meter stick accurate to within 1 cm. You may also give, if necessary, an apparatus diagram.
- Provide tables showing your measurement with units.
- Describe the uncertainties: standard, instrument, random errors
- Provide graphs. Graphs should be neat, clear, and include the axis label and units.
- Computation of the final answer: slope calculation, averages, and standard deviations all in proper significant figures.
- Present your findings from the experiment.
- Evaluate the outcome objectively, taking a candid and unbiased point of view. Suppose that the outcome is not close to what you expected. Even then, after checking your results, give reasons why you believe that outcome is not consistent with the expected. Make it plain, simple. Make factual statements such as “graph 1 shows a linear variation of velocity with time”.
- State the discrepancies between the experimental results and the model (theory), and discuss the sources of the differences in terms of the errors by offering logical inferences.
- Suggest improvements
Although these do not make an exhaustive list of do’s or don’ts, they nevertheless offer a framework around which one can write an effective report. In our experiment, some of the items indicated under each section may not be needed. I will give you more feedback in class. I expect that, the lab reports, either typed or handwritten, should be neat, clear, and organized. Points will be deducted for these, as well as for missing units and failing to follow the outline (i.e. title, introduction, procedure, results, conclusion) given above.