Writing Science Laboratory Reports

There is no universally accepted format for a lab report. However, the purpose of any lab report should be to record your findings and communicate what you have learned. With these goals in mind, here are MY guidelines for writing a lab report.

Title:The title should clearly describe the nature of the experiment. In some

cases, you may be able to use the title of the lab your teacher provides.However, be sure that the title provides clear information. Don’t forget to include your name and the lab date above your title.

Abstract: Though this section appears second in the report, it iswritten LAST. This section summarizes the purpose of the experiment andyour findings. It gives the reader a quick overview of what you’ve done andwhat you’ve learned.

It should start out “The results of this experiment were…” or something similar.

Introduction:This section should describe the problem or hypothesis youare investigating. The introduction should include the reason you are studyingthe problem and any useful outside information related to the problem or your hypothesis. It should also include your hypothesis or what you think will happen. Ways to start are “In this experiment we are to…”; “We will be doing this experiment to prove…”; “The following information is known…”; and “I think this will happen as a result of the experiment…”

Methods or Procedures: This section describes your procedure, the materials

used, how you gathered and analyzed your data, and the controls inyour experiment. This can be listed “stepwise” or summarized in a paragraph.

Data or Results: In this section, you describe what you found out through the experiment.Results include your observations, measurement data, graphs, andtables.

Calculations: Any result that you had to calculate should be shown in the calculation section. Only one example of each calculation should be noted.For example, if you determined the density of a metal that is listed in the data, show how you determined its density using a sample calculation:

D = M/V, D = 5.00 g/2.5 mL = 2.0 g/mL

Conclusion: A good conclusion (1) summarizes the purpose or objectives of the lab; (2) discusses your hypothesis or prediction prior to doing the lab; (3) discusses your results and (4) makes a conclusion or interprets your results. For example, if the objective of the experiment was to determine the density of several metal samples, how did you do this? What results did you obtain? How did they compare to the results you predicted or should have gotten?

Sample Report
Tyler Fleegenshneeze August 11, 2001
Title: Making a Seismograph
Abstract: My results showedthe harder the table was being hit, the higher the amplitude rose.
Introduction: In this experiment, we will be investigating how hitting the table (a magnitude of vibration) affects a pen as it hangs over a piece of paper (the amplitude of the seismograph). I predict that an increase in the magnitude of vibrations will result in an increase in amplitude of the seismograph.
Procedure: I laced a piece of paper directly beneath the pen and the clamp stand. One person slowly moved the paper past the pen, as the other hit the end of the table. The first trial represented a medium magnitude movement. The second trial was the soft movement, and the third was the hardest, or the most forceful magnitude. While looking at each individual seismograph, the greatest magnitude was observed and identified. Measuring the distance from the top and bottom of the spike represented the amplitude. The data from each seismograph was recorded in the table on the following page.
Magnitude / Amplitude / Observations
Medium #1 / >1.3 cm. / a little jagged, the dots are the darkest of all the trials, the pen a little wild
Softest (#2) / >.5 cm. / the smoothest line, more dots and dots are closer together, the pen was not out of control
Hardest (#3) / 2 cm. / the most jagged, doesn't really have a certain path, the least amount of dots, pen way out of control
Conclusion: This lab investigated how the magnitude of vibrations affects the amplitude of a seismograph. In order to study the problem we created three magnitudes of movement and measured the amplitude of each with a seismograph. My results showed the trial with the greatest amplitude was trial three because the table was being hit with the most force, making the table and the pen move more than the other three trials. The trial with the least amplitude was trial two because the table was hit with the least amount of pressure. While observing the experiment, I noticed that the more vibrations or higher magnitude resulted in a higher amplitude on the seismograph. The harder the table was being hit, the higher the amplitude rose. This proves my hypothesis was correct.
I believe the results are accurate because while the experiment was in progress, the frame moved at the same rate as the table. It was proven in trials one through three that the increased magnitude of table movement caused the greatest amplitude differences on the seismograph. It is clear, therefore, that the movement of the frame also corresponds to the amplitude of the seismograph. The bar and marker shared the same relationship with the table and the frame. The more the frame moved, the greater the amplitude on the seismograph.
In order to further investigate this problem, next time I would try the experiment on a different surface and would add additional movements of varying forces for further readings on the seismograph.