Intro. to Cellular and Molecular Biology 23.161
Department of Biology
Framingham State College

WRITING LAB REPORTS

A scientific paper usually includes the following parts: a title (statement of "what it's about"), an abstract (short summary of the paper), an introduction (background and significance of the problem), a Materials and Methods section (report of exactly what you did), a Results section (presentation of data), a Discussion section (interpretation of results and conclusions), and references (books and periodicals used).

Title Page and Title

The title page is the first page of the paper and includes the title of the paper, your name, the course title, your lab day, and the date. The title should be brief and informative. It tells the reader "What it's about" and thus should summarize the subject of the report in the minimum number of words. 

Introduction

In the introduction you say "Why I did it". The introduction serves two functions: (1) to provide the context for your investigation and (2) to state the question asked and the hypothesis tested in the study. Begin the introduction by reviewing background information that will enable the reader to understand the objective of the study and the significance of the problem, relating the problem to the larger issues in the field. Include only information that directly prepares the reader to understand the question investigated. Most ideas in the introduction will come from outside sources, such as scientific journals or books dealing with the topic you are investigating. All sources of information must be referenced and included in the References Cited section of the paper, but the introduction must be in your own words. Place the author of the reference cited and the year of publication in parentheses at the end of the sentence or paragraph relating the idea, for example, "(Goldfarb et al., 1993)."

Following the background information and near the end of the introduction, you should briefly describe the experiment performed and the outcome predicted for the experiment; include only the question and hypothesis that you finally investigated. It is a good idea to write down each item (question, hypothesis, prediction) before you begin to write your introduction.

Write the introduction in present tense when relating the background information (i.e., when referring to another investigator's published work) but use past tense when referring to your experiment. Paradoxically, most people find it easiest to write the introduction after the rest of the paper is completed.

Materials and Methods

The Materials and Methods section tells "What you did". It describes your experiment in sufficient detail so that another researcher could repeat your work. Write the Materials and Methods section in paragraph format in past tense. Be sure to include levels of treatment, numbers of replications, and control treatments. If you are working with living organisms, include the species and sex of the organism if that information is relevant to the experiment. Do not include failed attempts.

Write the procedures used concisely, but in paragraph form. The difficulty comes as you decide the level of detail to include in your paragraphs. You must determine which details are essential for the investigator to repeat the experiment. For example, if in your experiment you incubated potato pieces in different concentrations of sucrose solution, it would not be necessary to explain that the pieces were incubated in plastic cups labeled with a wax marking pencil. In this case, the molarity of the sucrose solutions, the size of the potato pieces and how they were obtained, and the amount of incubation solution are the important items to include.

Results

The Results section tells "What you found". It consists of at least three components: (1) one or more paragraphs that describe the results, (2) figures (graphs, diagrams, pictures) and (3) tables.

The Results are the meat of the report and this section should be completed first. The Results are presented as data in graphs, tables, and other illustrations (figures). The tables allow you to present your results clearly to the reader, and graphs allow you to visualize the effects that the independent variable has had on the dependent variables in your experiment. You should study these data and arrange the tables and figures according to the arguments you wish to present, and then write the text to explain them.

The written part of the results should consist of a description of important trends and relationships shown by the illustrations. In addition, observations that are not easily diagrammed may be pointed out. This section is not a mere translation of the graphs or tables into words. Report your data as accurately as possible as it happened. Do not report what you expected to happen in the experiment in the Results section. Also, do not discuss the meaning of your results in this section.

Figures and tables should be numbered consecutively throughout the paper (for example, Figure 1, Figure 2, etc. or Table 1, Table 2, etc). Refer to figures and tables within the paragraph as you describe your results. If possible, place each figure or table at the end of the paragraph in which it is cited. In addition, each illustration must have a heading and a legend that describes the relationship illustrated the type and number of animals used, and the statistics used. For example, a figure heading might be "Seasonal Variation in the Mean Testes Wet Weight in Rana pipiens". The legend might be "Each point represents the mean of 6 animals and vertical lines indicate the standard error". Moreover, the axes of each graph must be labeled with the parameters and units represented, e.g., "Average uterine wet weight, mg/gm body weight".

Discussion

In the Discussion you say "What it means". This is where you analyze and interpret the results of your experiment. State what the results show, whether your results agree with previously published work and why or why not. You should also state your conclusions in this section. Do not use the word prove in your conclusions. Your results will support, verify, or confirm your hypothesis, or they will negate, refute, or contradict your hypothesis; but the word prove is not appropriate in scientific writing.

Complete your Results sections before you begin writing the discussion. The figures and tables in the Results section will be particularly important as you begin to think about your discussion. Studying these data will be one of the first steps in interpreting your results. As you study the your data in the Results section, write down relationships and integrate these relationships into a rough draft of your discussion.

The following steps may be helpful to you as you begin to organize your discussion:

1. Restate your question, hypothesis, and prediction.

2. Answer the question.

3. Write down the specific data, including results of statistical tests.
 

4. State whether your results did or did not confirm your prediction and support or negate your hypothesis.

5. Write down what is known from previous work about the biology involved in your experiment. How do your results fit in with what was previously known?

6. State the significance of your results.

7. List weaknesses you have identified in your experimental design. You will need to tell the reader how these imperfections may have affected your results.

8. List any problems that arose during the experiment itself. Unforeseen difficulties with the procedure may affect the data and should be described in the discussion.

 Having completed this list, integrate all of this information into several simple, clear, concise paragraphs.

References Cited

The References Cited section lists those (and only those) references cited in the paper. In the text of your paper, cite the references using the author's name and year. For example:

The import of proteins into the mitochondria has been widely studied (Low and Behold, 1995).

Low and Behold (1995) has described the import of proteins into the mitochondria.

 Use the following format to list research papers in the References Cited section: Low, P.J. and Behold, R.F. 1995. The import of proteins into mitochondria of Tyrannosaurs rex. J. Irreproducible Sci. 234:375-386. Use the following format to list books in the References Cited section: Campbell, N.A. 1996. Biology, 4th ed., The Benjamin/Cummings Publishing Co., pgs 214-215. List articles from an edited book as follows: Neri, R. 1987. The pharmacology of methyoxychlor. pgs 16-23 in B.J. Furr and A.E. Wakling, eds. The Pharmacology of Pesticides. Academic Press, London. Reminders: As you begin writing your paper, refer to the following hints on how to make your writing stronger: 1. DO A FIRST "ROUGH DRAFT" AND REVISE IT BEFORE HANDING IT IN.

2. Write clearly in short, logical, but not choppy sentences.

3. Use past tense in the Abstract, Materials and Methods, and Results sections. Also use past tense in the Introduction and Discussion when referring to your experiment.

4. Write in grammatically correct English.

5. When referring to the scientific name of an organism, the genus and species should be in italics or underlined. The first letter of the genus is capitalized, but the specific epithet is written in all lowercase letters; for example, Drosophila melanogaster.

6. Use metric units.