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Section 5.17 Writing Lab Reports

Lab reports are a common genre of writing used in the sciences to convey the results of a scientific experiment and place them in the context of knowledge in the field. Do not underestimate the importance of the report: a scientific experiment has little value if its purpose and results are not communicated clearly! Lab reports are also a building block to writing a publishable thesis or scientific paper. While lab reports in most scientific disciplines have similar sections and share some stylistic expectations, emphases and conventions vary across disciplines. As a student in the sciences, engaging with these differences will help you apply your scientific writing skills in different classes.

Structure is important to lab reports in all scientific disciplines, and with some variations they use the same basic sections. This chapter includes an overview of the basic principles of each lab report section and uses examples from different scientific disciplines to examine the similarities and differences between them. The focus is on biology and chemistry, the disciplines where most students write lab reports at the 100- and 200- level. However, the general sections should be useful for other disciplines as well. While sections are presented in order here, it’s much easier to write out of order: begin with the methods and results, then move to the introduction and discussion, and write the abstract last!

Note 5.17.1. Examples.

Biology examples are drawn from student work from Biology 111, written on an experiment about photosynthesis in Elodea canadensis. Chemistry examples are drawn from student work from Chemistry 110, written about experiments to determine the identity of unknown gasses or unknown salts. They are student work and not perfect in every way, but useful for examining these concepts! For another example of an exemplary annotated upper-division lab report in biology, see the biology department student webpage 1 . In addition, handouts and examples from your professor are always an excellent resource, as are published scientific papers in your discipline.

Note 5.17.2. Style for Lab Reports.

Technical writing in the sciences uses clear, concise style with somewhat strict conventions. One source of confusion is the use of active and passive voice, which is an ongoing debate in scientific fields. Proponents of passive voice suggest that it maintains scientific impersonality, while those who prefer active voice argue that it is clearer or that authors should claim ownership of their work. Use of passive voice in the sciences may be declining (check out this article 2 ). For more on the mechanics of passive and active voice, see Subsection 7.3.3. For other disciplinary stylistic preferences, see the section of this chapter focused on your discipline.