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BIOL 111L: Cell Biology Lab - Christensen & Anderson: How to Write a Scientific Report by Dr. Brian Wisenden

Structure of primary literature by Dr. Brian Wisenden

Good scientific writing clearly and efficiently communicates experimental findings to other researchers. Because scientists produce and consume large quantities of information, scientific writing follows a standard format that allows the author and reader to quickly ascertain the most important parts of the study:

  1. What was the question?
  2. How was it tested?
  3. What did the author(s) find?
  4. What do these results mean?

These questions are organized in the report into separate sections as:

  1. Introduction
  2. Materials and methods
  3. Results
  4. Discussion

Introduction

The introduction starts with an introduction to the general phenomenon under study. The reason for starting off with a general overview is to establish a broad framework for the research question. The reader may not yet know much about the specific area of the research question, but the reader should know about the general area. A broad beginning allows the reader to relate their existing knowledge to the specific research question that is the focus of the report. It is important to cite your sources in the text of the introduction using standard format convention (see below). Once the framework has been established the introduction narrows to discuss application of the general phenomenon to a specific study system, including citations to existing work already done on the specific area. The introduction ends with a statement of the specific study question that was tested in the study.

How to cite references in the introduction

Sources are cited usually at the end of a sentence using author(s) and year. For example:

One author: Once chemical alarm cues of conspecifics have been detected, the receiver is primed for releaser-induced recognition learning (Suboski, 1990).

Two authors: Behavioral correlations such as that between the tendency to explore novel areas and boldness in the face of predation risk likely reflect shared, genetically-based proximate causations (van Oortmerssen and Bakker, 1981).

More than two authors: Embryonic responses to ambient information are known for food preferences in cuttlefish (Darmaillacq et al., 2008).

 

Note several things about these examples:

  1. The first initials of the authors are not included for in-text citations.
  2. There are no quotations anywhere, ever. Quotations are used for writing in the humanities, but not here.
  3. et al. is italicized because they are non-English words. et has no period after it but al. does because it is the abbreviation of alia. et al. is Latin for ‘and others’.

Materials and Methods

The materials and methods begins with a description of the study system and source of materials and then proceeds to the methods (or protocols) used to test questions. If there are multiple experiments, usually each experiment is described separately. The description of the materials and methods section must provide enough detail for others to be able to duplicate your experiment but nothing more. Always use full sentences in this section. It is not acceptable to provide a bullet list of materials and equipment. References to other sources where standard methods are described in detail IS acceptable.

Results

This is the most important section of the report. The results section is a brief narrative of the findings of your study. Because it is a narrative, you must start with words, not tables and figures. References to the results of statistical tests are imbedded within the narrative, usually at the end of a sentence. Examples:

  1. Feeder position significantly affected female hummingbird preference (F4, 98 = 2.819, P = 0.029; Fig. 1).
  2. We found that the reaction time of fishes to the mechanical heron was significantly affected by the shoal size (F2,45 = 50.47, P < 0.001, Table 1).

Note that there are two forms of results; figures and tables. Figures have x and y axes. Tables have columns and rows. Figures and tables summarize the main findings of the study into a form that makes it easy for the reader to see the main trends. Raw data are never reported. Note also that statements that include the word ‘significantly’ must be supported by statistical inference. Also, there is no interpretation of the significance of these findings or citation to other studies. That is left for the discussion section.

Common error in reporting the results:

  1. Starting results section with a table or figure instead of text
  2. Format: Correct format is tables have headings above, figure have legends below
  3. Graph: make sure to include standard error bars, label the axes, delete grid lines and title
  4. Presentation of raw data is not helpful. A graph or table that summarizes the main findings for the reader is best.
  5. Data is a plural for datum. Hence, “these data were analyzed” is grammatically correct while “the data was analyzed” is grammatically incorrect.
  6. Always place a zero in front of a decimal for P values.
  7. The ‘t’ in t-test is always lower case t.

Discussion

The discussion is the place for interpretation of the results. Start the discussion with a restatement of the main finding of the study. Then compare your results with results from other similar studies (and cite your sources!). Finish by looking ahead to where your results may lead future studies. Although every study has elements that may have not quite gone as planned, we generally do not dwell on it in the discussion.

References

The formatting for references is one of the most difficult things for students to get right. And yet, it is so straightforward. Simply copy the format of the examples below.

Darmaillacq, A. S., Lesimple, C. and Dickel, L. 2008. Embryonic visual learning in the cuttlefish, Sepia officinalis. Animal Behaviour 76: 131–134.

Suboski, M. D. 1990. Releaser-induced recognition learning. Psychological Review 97: 271–284.

van Oortmerssen, G. A. and Bakker, Th. C. M. 1981. Artificial selection for short and long attack latencies in wild Mus musculus domesticus. Behavioral Genetics 11: 115-126.

Note:

  1. No quotations are used anywhere, ever.
  2. The first names of the authors are not spelled out. Only the initials are used.
  3. Nothing is underlined.
  4. The volume issue is not reported.
  5. There is no url or web address information included.
  6. These are all peer-reviewed sources.