Example 4: Writing Lab Reports for Dr. Kirsten Work (These scientific paper guidelines excerpted from the Biology II laboratory manual from Spring 2011):
After completing projects in your Biology classes, you will need to write lab reports to demonstrate what you have learned during the process (how thoroughly you collected background information, how you conducted the experiment, what you found out, and what it all means). Whether you are writing a paper for an English, Sociology, or Biology class, you must always produce something that convincingly conveys information…in other words, well-written and well thought out. The formats used in each discipline, however, are very different; you must conform to certain scientific writing conventions described below.
TITLE – The Title should convey some meaningful information about what the experiment did. For example, you can’t just use the title of the chapter in the lab manual. Imagine if you were searching on the web for articles to use in a report…you initially use the titles to decide whether an article will be useful. Can you see why the second of the two titles below gives you the best information and why the first is virtually useless?
(1) Catfish reproduction
(2) Reproduction in an invasive exotic catfish, Pterygoplichthys disjunctivus, in Volusia Blue Spring, FL, USA
ABSTRACT - The Abstract is a summary of the report. Basically, it includes a sentence or two each of introduction, methods, results and discussion. The Abstract should start with a sentence that introduces the topic of the experiment and then a statement of the hypothesis that was tested. The next sentence or two should provide a very brief description of the methods employed to test the hypothesis. The main findings are presented in a sentence or two followed by a statement of the main conclusion.
INTRODUCTION – Here you are setting the stage for your experiment. Start with the big picture and work your way towards a hypothesis. You need a good reason for posing a particular hypothesis…a hypothesis is an educated guess, so show the education part! You should refer to at least two published research or review articles…Why? Because you need to show where you got your information, and that it is a reliable (scientific) source that anyone else can also look up. If, for example, you plan to look at the effects of pollutants on frog development, you need to devote a few sentences to the issue of aquatic pollution. You should devote a few sentences to frogs and their development from eggs to tadpoles to adults. At this point you are ready to point out a “problem” (something that needs to be investigated), and a “question” that you think your hypothesis answers. For example, there is a lot of water pollution in the waters where frogs lay their eggs (problem). Is frog development negatively affected by pollutants? (question). You can hypothesize that frog eggs exposed to the common yard chemical malathion will not develop normally, and these abnormalities will increase with increasing concentrations of malathion (hypothesis). Always be sure to state your hypothesis clearly….”We hypothesized that…”, or “I hypothesized that…”; the word hypothesis must be used.
METHODS – This section describes how you collected and analyzed the data. You need to provide enough detail so that someone else could use your report to replicate the experiment. Remember that science is all about being able to replicate another scientist’s results; if you can’t do that, something is wrong with their methodology or your use of it.
Never use lists or tell the reader what had to be done or should be done; simply explain what you did. Be sure to include all relevant details: concentrations of solutions, temperatures, species names, equipment used, statistical tests used, etc. Since you did the experiment, write this in the first person.
RESULTS – Here you present your results graphically and summarize key findings without explaining what your results mean.
Your choice of graph type is important, as it says something about the data. Line graphs tell you that the data are continuous (e.g. the amount of oxygen produced by a plant over time), whereas bar graphs show discontinuous data (e.g. how well yeast metabolized four different food sources). Graphs may be constructed differently in different disciplines; in the sciences, the independent (manipulated) variable is on the x-axis, and the dependent variable (the result) is on the y-axis. Everything on the graph must be labeled (axis units, axis label, overall title, and sometimes a legend). Figures should never be embedded in the text; each one belongs on a separate page, and all figures should follow the Literature Cited section at the end of the report.
After generating your graphs, write a few sentences that point out the highlights and patterns of the data in the graphs. Be sure to point out anything you think is particularly interesting. You don’t want to restate what is already in the graph. Don’t forget to refer to your figures in the text of the results (e.g.“The higher the concentration of glucose, the more carbon dioxide was produced by yeast (Figure 1)”….not “The results are shown in Figure 1”). Be sure to mention the results of whatever statistical tests you ran, whether the results are statistically significant, and what the p-value is.
Each graph should have a short title and a caption that clarifies what is in the figure (defines symbols, explains statistics, etc.). The title and caption should be placed below the figure. The easiest way to format the figure properly is to make the graph in Excel and then copy and paste into Word. The title and caption can be written on the line below the figure.
DISCUSSION – In this section you interpret your results. Start off by briefly summarizing your finding and how those findings relate to your hypothesis. Clearly state whether your hypothesis was supported or not (hypotheses are not proven or shown to be correct). Use the rest of the discussion to really go into detail about what you found (trends, etc.) and why you think the experiment turned out the way it did. Relate your findings to those of other groups in your lab, and to published work. Point out any influences that the experimental design or data analyses could have had on the results. Were there any sources of error? Things that went wrong? Use a few sentences at the end to summarize findings and what should be done in future studies (new questions to answer, and/or new ways to answer those questions experimentally).
ACKNOWLEDGMENTS – Thank anyone (including lab mates) who helped you complete the experiment. Never say “I would like to thank….”; that implies that you don’t actually thank them…go ahead and thank them (“I thank….”).
USE OF REFERENCES AND LITERATURE CITED – This is not a bibliography, so all sources listed must be cited in your report. Follow APA style or the CBE Author-Year system. When citing an article or book in the text of your report, you must include the author’s last name and date of publication (Gibbs, 2007)….never use the page number (Gibbs, 112).
Why? Scientists often publish more than one paper on the same topic, so page numbers would not be very useful if you tried to find the right article in the Literature Cited section and found that Dr. Gibbs had 6 articles published on similar topics! It would be a real pain to have to look through all 6 articles to find the bit of information you wanted.
Articles or books cited in your paper must be listed alphabetically in the literature cited section of your report using the following format:
Gibbs, M.A. (2003) A Practical Guide to Developmental Biology. Oxford University Press, Oxford. 118 pp.
King, M.S. (2006) Anatomy of the Rostral Nucleus of the Solitary Tract. In Bradley, R.M. (Ed.), The Role of the Nucleus of the Solitary Tract in Gustatory Processing, Taylor and Francis Group, Boca Raton, FL., pp. 17-38.
Work, K.A, Havens, K.E., Sharfstein, B., and T. East (2005) How important is bacterial carbon in the planktonic food web of a turbid, subtropical lake? J. Plankton Res. 27: 357-372.