Guide to Writing Scientific Laboratory

Experiment Reports

 

Breakdown of Marks (/100):

Abstract:                           5
Introduction:                    30
Experimental:                   10
Results and Discussion:    40
Conclusions:                      5
References:                      10

     The ACS Style Guide1 is an excellent source of information on how to write a scientific laboratory report.  Text should be double-spaced, left-justified and written in the impersonal, passive voice.  Written laboratory reports will usually be ten to twenty pages in length in total, but this number depends on the experiment that was performed and the amount of data collected.  There are seven distinct sections that are crucial to a laboratory report or journal article:

1. Title and Author: The title should be both succinct and clear. It describes the experiment in approximately four to thirteen words and should be written last, when the author has a clearer understanding of the experiment.

2. Abstract: The abstract is a brief, three to six sentence summary of the experiment.  The abstract is the author's opportunity to highlight outstanding features of the experimental results, such as new reaction pathways, spectroscopic results, synthetic discoveries or difficulties that were overcome.  It is a good idea to include pertinent quantitative results, such as percent yield.  A browsing reader often reads only the abstract of a paper in a scientific journal.  It is here that the author has the opportunity to showcase his work and entice the reader to read the entire article.  As for the title, the abstract should be written last.

3. Introduction: The introduction is generally two to three pages, in which the author summarizes a particular class of inorganic compounds or materials, via its synthesis-structure-property-application relations.  The author should address the basic questions, 1) Why was this experiment undertaken and why is it of interest?  2) What are the key aspects of the compounds or materials being studied that make them of interest?  3) What has been done by others to date?  Be sure to use literature references, numbering sequentially and place them in the references section (see below).

4. Experimental: The experimental section is written as prose (not point form), and uses the past perfect tense, and the passive voice, to explicitly and sequentially describe the actual experiment.  This will enable other scientists to duplicate your work.  This section includes, but is not limited to: a complete description of the reagents, including the order, quantities and method for their addition; a written description of the experimental apparatus, including brand and model numbers where appropriate, and may include a drawing of more complex apparatus.  Many authors write the experimental section first, since this section reports the method in a conventional format, without the need to explain the results.

5. Results and Discussion: The results and discussion section presents the data that was acquired in the experiment and interprets the data.  All tables and figures should be properly labeled, sequentially numbered and contain a caption that is in English: if one reads the caption on its own, it is a complete sentence.  Spectra and graphs should clearly display axis labels and units, and pertinent peaks should be assigned for spectroscopic data.  While the experimental section delineates specific details that may include quantities and grades of reagents, this section summarizes the reactions and discusses the impact of the results from a theoretical and technical viewpoint.  The experimental results are compared with those reported in the literature.
     If the author prefers, the results and discussion section may be broken into two separate sections.  These sections overlap and it is sometimes easier to deal with one section at a time.  In this case, the results section will display or summarize the data collected, while the discussion section will interpret the data.

6. Conclusions: What does it all mean?  The conclusions are *not* a simple summary of the experiment, or a repetition of points that were made earlier in the report.  It should be one or two paragraphs in length, and tie together all of the data in a manner that makes some sort of statement as to the relevance of the results to the particular subarea of chemistry.

7. References: There should be at least ten, relevant literature references sited.  Scholarly, peer-reviewed, scientific journals and books are the primary source for these references; web sites are not a valid source.  The Chem445 lab notes were certainly used in the experiment and should be referenced.
     The writing format of the references should follow that found in the Journal of the American Chemical Society (JACS).  This journal is also a good source to see the ideal report format, overall.  See the appendix on prelabs for good inorganic chemistry journals and materials chemistry journals to look at.  There are many other sources in the Science Library for previously reported data: Chemical Abstracts,2 the Dictionary of Organometallic Chemistry,3 The Encyclopedia of Inorganic Chemistry4 and various books found through elixir.  Web of Science, http://webofscience.com/, is an excellent online database to which the University subscribes.  It allows one to search published reports and reviews of scientific journals by subject or author, and the student is strongly encouraged to use this information source.

 

References

1. The ACS Style Guide: A Manual for Authors and Editors; Dodd, J. S., Ed.; American Chemical Society: Washington, DC, 1986.  (Science Library, Reference Section, QD8.5 .A25 1997)

2. Chemical Abstracts; American Chemical Society: Columbus, Ohio, 1907- Present. (Science Library, Reference Section)

3. Dictionary of Organometallic Compounds, Buckingham, J., Ed.; Chapman & Hall: London, 1984. (Science Library, Call Number: QD 411 D53 1984)

4. Encyclopedia of Inorganic Chemistry, King, R. B., Ed.; Wiley: New York, 1994. (Science Library, Call Number: QD 148 E53 1994)