Lab Reports

Here is an outline for your students on how to write up a lab report from a science experiment. We attempt about 3-4 science experiments every week at my house. We write up an informal and brief outline for each. But I only require a formal lab report as outlined below on one experiment each month. This frequency may change as the kids grow older.

Heading: Title Experiment # Date Your Name Name of group members Instructor’s name Purpose: State the purpose of the experiment in one or two sentences. What is the goal of the exploratory process stated as specifically as possible. Background: (Only required in a formal lab report) The goal of the Background section is to inform your reader about the experiment so that your reader will have a clear idea of what you did, why you did it, and what your results mean. This section should include the elements below in the order listed. For high school science reports, this section of the report will require from one to four paragraphs depending on how complex the theory and the experiment are. • History – If your experiment relates at all to principles discovered in the past, always include a bit of history, but make your comments brief and specific to the theory or law you are working with. • Theory – Describe the theory your experiment is base on. If the theory includes equations, state and explain them here. Also explain what they will be used for in your experiment and what the variables mean in each one. • Overview of experimental plan – In a few sentences outline the general approach followed in the experiment and the major pieces of equipment you used. The goal here is to give the reader a basic idea of what is going on so that your description later of the detailed procedure will make sense. If you are using a theory to make predictions, explain how this will be done. It is appropriate to do this here, after the experimental plan has been explained. • Hypothesis – Conclude the Background section with a specific statement of your experimental hypothesis. (This only applies if you are writing up a hypothesis-driven experiments.) Experimental Procedure: Describe “what you did” Supply list first Describe your experimental procedures and methods in detail. Watch your verb tenses and make your methods crystal clear to the reader. Avoid using pronouns. No data included in this section. Results: Describe “what happened” • Present your data in tables (Unless there are just 1 or 2 values) Label the tables, title them and refer to each of them, in order, in the text before they appear. • If you were required to make qualitative (relating to or based on the quality or character of something) observations during the course of the experiment, describe them here. • Do not begin interpreting your results here; that is to be done in the Discussion section. Here just state what happened. • Don’t forget to present every value of every variable. If there are not enough variables to place in a table make sure you state them in a complete sentence. They cannot just be written on the paper. Always state units of measure. Discussion: • The goal for this section is to analyze and discuss your results. • Spell out what you learned. Describe how this experiment illustrated the theory/concept you were learning about. • Determine if your hypothesis was confirmed. Judge whether your results were definitive or inconclusive, regardless of whether or not the hypothesis was confirmed (if it was a hypothesis driven experiment). Conclusion: Summarize your results, how definitive they were (were the results consistent or inconsistent, did they point to an obvious conclusion), and their relationship to the hypothesis. Wrap it up with an overall judgment about how successful the experiment was. Keep your comments strictly on your experiment, your findings, and your recommendations for improvements to the experiment or for future research. It is appropriate to suggest specific ways the experiment could be improved. References: You will not often have references at this level in science. Just in case you do use the MLA format to cite them. Reports must be typed with single-spaced text, 1-inch margins, 12 point Times New Roman All text black – only color for graphs if you want, not required Reports should look clean, neat, and plain. Plain is good. Lab reports belong to the literary genre known as technical writing. The purpose is to be clear and unambiguous, technical writing is plain, dry, and free of rhetorical ornament. If adjectives are used they need to be used consistently throughout the lab report. If a substance is “smooth”, it needs to be “smooth” the next time too – not “flat” – Only change adjectives when you want to make a distinction between substances. Audience: An intelligent person who is mathematically competent and who has a working scientific vocabulary, but do not assume that the audience was present at the experiment or has any idea of what the experiment was about.