Writing for Botany
Chapter 5 - How to Write a Laboratory Report
A scientific paper . . . has only one purpose; it must persuade the reader of the veracity of the observer, his disinterestedness, his logical infallibility, and the complete necessity of his conclusions.
J.M. Ziman
Doing an experiment is not more important than writing.
E.G. Boring
Only when he has published his ideas and findings has the scientist made his scientific contribution, and only when he has thus made it part of the public domain of science can he truly lay claim to it as his. For his claim resides only in the recognition accorded by peers in the social system of science through reference to his work.
R.K. Merton
Without publication, science is dead.
Gerald Piel
Work, finish, publish.
Michael Faraday
Your laboratory instructor may occasionally ask you to write a report that describes the work you did in lab. Although your report will probably not be published, the exercise is nevertheless important because it will help you learn to write a scientific paper.
Before reading this chapter, go to the library and browse through a few botanical journals such as Planta, Plant Physiology, and American Journal of Botany. Make photocopies of one or two of the articles that interest you. You'll notice that just as sonnets conventionally have 14 lines, so too do scientific papers (and lab reports) have a standard format. That format, which reflects the scientific method, is as follows:
- Title
- List of authors
- Abstract
- Introduction
- Materials and methods
- Results
- Discussion
- References
Understanding this format eases the burden of writing a lab report and scientific paper, since writing is an exercise in organization. Refer to the journal articles that you photocopied as you read this chapter.
The title of a paper announces the topic of the paper. It is a short label (usually less than 12 words) that helps readers quickly determine their interest in the paper. The title should reflect the paper's content and contain the fewest number of words that adequately express the paper's content. The title should never contain unusual abbreviations or jargon (overly specialized or technical language).
Here are some typical titles of botanical papers, along with where the articles are published:
- Mutations affecting body organization in the Arabidopsis embryo
(Nature 353: 402-407; 1991)
- Pathogens, patterns, and processes in forest ecosystems
(BioScience 45: 16-24; 1995)
- Signaling the arrest of pollen tube development in self-incompatible plants
(Science 266: 1505-1508; 1994)
- Two endogenous proteins that induce cell wall extension in plants
(Plant Cell 4: 425-433; 1992)
Only those people who actively contributed to the design, execution, or analysis of the experiment should be listed as authors. Anyone listed as an author should be willing to publicly claim and defend the paper.
The Abstract is a short paragraph (usually less than 250 words) that bridges the title and text of the article. An abstract presents the essence of the paper by summarizing (1) the objectives and scope of the problem, (2) methodology, (3) data, and (4) conclusions. An abstract contains no references.
The Introduction orients readers, states why you did the work, and gives readers enough information to understand and appreciate the rest of your report. When writing the Introduction, avoid exhaustive reviews of what has already been published; rather, limit the Introduction to just enough pertinent information to orient the reader to your study.
The Introduction of a scientific paper has two primary parts:
- A description of the nature and background of the problem. For example, what do we already know (or not know) about this problem? This is developed by citing other scientists' work (i.e., a historical description of the problem) and by pointing out gaps in our knowledge.
- The objectives of the work. These are best stated with a topic sentence such as "The objectives of this work were . . ."
The Materials and Methods section describes how, when, where, and what you did. It should contain enough detail to allow another botanist to repeat your experiment, but should not be overwhelming.
- Materials include items such as growth conditions, organisms, and the chemicals used in the experiment. Avoid trade names of chemicals, and describe organisms with their scientific names (e.g., Zea mays cv. Yellow Dent, rather than "corn"). Also describe growth conditions, lighting, temperature, etc. For most lab reports, do not copy the experimental procedures word-for-word; instead, summarize what you did in a few sentences or refer to a previously published description of the method (e.g., We prepared the tissues for microscopy according to methods described by Wayne [1995]).
- Methods are usually listed chronologically and are subdivided by paragraphs and headings. Examples of methods include sampling techniques, types of microscopy, numbers of replicates, and statistical analyses. If possible, use references to describe methods.
Experiments described in a lab report and scientific paper must be reproducible. Thus, the quality of the Materials and Methods section is judged by the reader's ability to repeat the experiment. If a competent botanist can repeat your work, the Materials and Methods section is well written.
The Results section is the heart of a scientific paper, and should clearly summarize your findings without any implications regarding their possible importance. For example, state that "All of the plants died within 10 days after germination" or "Table 1 shows the influence of 2,4-D on stem growth." Keep it simple and straightforward.
There are many ways to present results. The particular method that you choose should depend on what you want to show.
| Method
| |
Used to show |
| Photograph |
|
Detail |
| Line drawing |
|
Outline essential parts |
| Pie chart |
|
Percentages |
| Flow chart |
|
Steps in a process |
| Bar graph |
|
Values at a specific time or stage |
| Line graph |
|
Values over time |
| Exploded diagram |
|
How parts fit together |
| Table |
|
Large amounts of numerical data |
Graphs are an excellent way to summarize data and show the relationships of independent and dependent variables:
- The variable that the botanist established and controlled during the experiment is the independent variable, and is presented on the x axis of the graph. For example, daylength could be an independent variable in an experiment studying the induction of flowering. Similarly, time and temperature are often independent variables.
- The dependent variable changes in response to changes in the independent variable, and is presented on the y axis of the graph. Mass and growth rate are examples of dependent variables that can change in response to light, temperature, etc.
Graphs must also have a title (e.g., The Influence of Temperature on Root Elongation), labeled axes (e.g., Temperature, Root Elongation), and scaled units describing the variables (e.g., ºC, mm h-1).
It's not enough to only report your findings; you must also discuss what they mean, how they relate to existing knowledge, and why they're important. This is the purpose of the Discussion section of a lab report or scientific paper.
The Discussion section should interpret your results relative to the objectives that you described in the Introduction and answer the questions "So what?" and "What does it mean?" Thus, a good Discussion section should do each of the following:
- Discuss your findings--that is, present relationships, principles, and generalizations. Point out exceptions and lack of correlations. Don't conceal anomalous results; rather, define unsettled points. State how your results relate to existing knowledge.
- State the significance and implications of your data. What do your results mean? Don't be shy; if your data are convincing, don't hesitate to use statements such as "We conclude that. . . ."
Scientists rely heavily on information presented in papers written by their colleagues. Indeed, the Introduction, Materials and Methods, and Discussion sections of a lab report often contain citations of other publications.
When citing other botanists' work, cite only what is necessary and avoid the urge to cite all of the available references to make your point. You'll get no glory by association; moreover, the increasing popularity of review papers (e.g., those published in Annual Reviews of Plant Physiology) make exhaustive reviews of the literature unnecessary. Your knowledge of the history and breadth of the problem that you studied will be revealed in how you describe your own work. There is no need to show it any other way.
The format for literature citations varies in different botanical journals. For example, Plant Cell requires authors to list references as follows:
-
- Fisher, R.F., and Long, S.R. (1992). Rhizobium-plant signal exchange. Nature 357, 655-660.
BioScience uses this type of citation:
-
- Franklin, J.F., H.H. Shugart, and M.E. Harmon. 1987. Tree death as an ecological process. BioScience 37: 550-556.
Your instructor will tell you how to format your citations in any papers that you write for your botany class.
Exercises
1. Go to the library and browse through recent issues of at least five different botany-related journals. How do they differ? Do they have different audiences? How can you tell? Which of the journals would you like to publish an article in? Why?
| Journal |
- - |
- - |
Features |
- - |
- - |
Audience |
2. Choose a paper from one of the journals you listed in Question 1. What hypotheses were the botanists testing? What were their assumptions? Do you agree with their conclusion? If given the chance, how would you rewrite the paper?
3. Go to the library and examine a botany-related thesis, research paper, review article, book, and newspaper article. How does the writing differ? How is it similar?
Thesis:
Research paper:
Review article:
Book:
Newspaper article:
4. Ask your reference librarian to conduct an on-line search for citations about a topic of your choice. How does the specificity of your topic relate to the number and usefulness of the citations that you obtain?
5. Write an abstract for a botany-related article of your choice in Scientific American.
Plagiarism occurs when a writer copies statements from another source without giving credit to that source. Sometimes, it is intentional. Sometimes it's not. In either case, it is a serious offense that is not acceptable. Indeed, a student guilty of plagiarism can face sobering consequences: getting an F on the assignment, being placed on disciplinary probation, or even being expelled from school.
Do not hesitate to use other botanists' ideas. All botanists do that every time they write a paper for publication. However, give credit to the writers of the ideas you use. Do that by citing the source of the original idea (Moore, 1992).
Search | How to Order | E-mail Us
Copyright ©1997 McGraw-Hill College Division