Writing the Conclusion Section of a Lab Report

The standard lab report will typically have 8 sections:


1. Title

2. Abstract

3. Introduction

4. Experimental

5. Results

6. Discussion

7. Conclusion

8. References

The Conclusion section states the most important thing learned during the lab and justifies how it was learned.  In cases where you could not meet your experimental goal, you may also comment on difficulties in experimental design/procedure or on future experiments you might do to achieve your experimental goal.  If you are inspired, you may comment on the real world implications of your data. The Conclusion does not need to be very long.  It could be as short as one sentence or as long as a paragraph.  In some situations it could be even longer, but in these labs a short conclusion will generally suffice.


            NOTE: The conclusion is usually a little bit redundant.  DonŐt worry about this.


One way to write the conclusion is to ask yourself a few questions:


1)    What was the single most important result of this experiment?

2)    How did I get my result?

3)    If my experiment didnŐt work, what procedure should be changed or what additional experiment should be done?

4)    What is the real world implication?


Questions 1 and 2 are necessary for all experiments.  Question 3 is for experiments that did not work well and question 4 is for when you feel inspired to take it a little further.




Example 1: Suppose a student did lab #9 (determination of the kinetic order of the crystal violet reaction) and found that the reaction was first order.

   Sample conclusion: Based on absorbance measurements and an integrated rate law analysis, it was determined that the reaction of crystal violet with hydroxide ion is first order with respect to crystal violet.


Example 2: Suppose a student did lab #9 (determination of the kinetic order of the crystal violet reaction) and had so much experimental error that it was impossible to determine the kinetic order with respect to crystal violet.

   Sample conclusion: In summary, the high level of noise in the absorbance data made it impossible to apply kinetic analysis to determine the rate law for the reaction of crystal violet with hydroxide ion.  Since the source of error was traced to the colorimeter itself, this experiment should be repeated with a vibrationally isolated spectrometer.


Example 3: Suppose a student used stress/strain measurements to determine how much force was necessary to break a rubber band.

   Sample conclusion: Based on stress/strain measurements, it was determined that 420 N of force are necessary to break a rubber band.  Since ligaments act like rubber bands in the body, this type of stress/strain experiment may also be helpful in determining how much force the body can withstand in contact sports.

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