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For a Well-Dressed Lab Report…Try a Vertical Bowtie!
Thursday, November 14, 2013

by Elizabeth L, Tutor Tango Staff Subject and Test Prep Tutor

The First Rule of Lab Reports is: Always follow your teacher’s instructions for the content and format of your report. The Second Rule of Lab Reports is: There are no other rules. To get the best grade, your report has to have what your teacher expects.

So I did ask my teacher, but I feel got the runaround. What now? No reason to panic. You now have the opportunity to self-organize and showcase your scientific writing. When college students ask me what to write in lab reports, I often advise the ‘Vertical Bowtie.’ This report is wide at the top, narrow in the middle, and big at the bottom.

Wide at the Top: The first part of your intro should be thematically wide, reflecting the most interesting and important idea of the lab. So often I read lab reports that begin like this: “The purpose of this lab was to separate plant pigments into X, Y and Z molecular weights.” Yawn! This narrow topic sentence was probably copied out of the lab manual (always a no-no) and doesn't show much independent thought. A more exciting opening would be: “Photosynthesis supports all life on Earth. This is only possible because plants have evolved a variety of light-capturing pigments, which can be separated biochemically.” This topic sentence is broad, interesting, and tells me that the student really understands the context of the lab work.

After starting wide, the rest of the Introduction should narrow down to the specific problem and experimental context. So, if your Big Idea is photosynthesis, the specific problem is how to separate pigments, and the experimental context is the plants you studied: “In this lab, we extracted leaf pigments from purple kale (Brassica oleracea) and green parsley (Petroselinum crispum) using alcoholic and organic solvents.” Notice that we do NOT go into any detailed methods here; save that for your Methods section.

Narrow in the Middle: By the end of the Introduction, we’ve provided a ‘roadmap’ to the specific problem and experimental context. The Methods and Results are therefore the most ‘narrow’ and focused sections of the report, giving the step-by-step of what you did and what you found. To format these sections, consult the First Rule of Lab Reports.

Big at the Bottom: After all the Methoding and Resulting, students often struggle with what to say in the Discussion. A common mistake is to say little or nothing, then stop: “These highly significant data confirm my hypothesis. That is all.” This dull ending is the last thing you want to write, because it is the last thing your teacher will read before handing out your grade. For a more memorable conclusion, reflect back on the inspiring Big Idea of the introduction. Repeat this theme and relate it to tour lab results and conclusions. Add a dash of enthusiasm and voilà! An intelligent, uplifting ending that will leave your teacher impressed: “These results show that plant pigments fall into two main chemical classes. As our climate is predicted to become warmer, plants with compound X may have an evolutionary advantage.”

Tie it All Together and Proofread: Even the perfect bowtie needs some adjustment. Once you have your report completely drafted, finish the look with an impeccable proofread. Check grammar, fix punctuation, trim sentences, and eliminate repetition among sections.

Bottom Line: Let’s face it. In almost every lab exercise, you and your classmates will use similar experimental methods and get similar scientific results. So what makes one person’s lab report truly great? It's the quality of thought in the introduction and discussion, and the quality of writing on every page. To dress for success, apply the Lab Report Vertical Bowtie!