Application of the Scientific Method

( The Goldfish Experiment )

Lab Exercise 1

Updated July 29, 2002
General Scientific Method Scientific Terms Resources Graphs
Graphs  Excel 
Charts -  general
line graph -  Excel - step by step
Assignment Tips Check List Quiz  


Check List for Your Report

Use this checklist to see that your report meets the guidelines
1. Type or wordprocess your report
2. Spellcheck your report
3. Write the report using the past tense 
4. Have a title page that includes the title, your name, section number and date 
5. Number each page after the title page
6. Use headings (Introduction, Materials and Methods, Results, Discussion, Conclusions, References Cited) 
7. Identify the organism, the response measured,and the environmental variable 
8. Include the hypothesis, the basis for the hypothesis, and the prediction used to test the hypothesis
9. Include at least one piece of information that you learned from a reference source 
Materials and Methods
10. Tell what was used at the time you tell how the item was used. Don't make a separate list.
11. Tell in words and paragraphs what was observed and what did result 
12. Place tables and figures (graphs) in the Results section 
13. Give each table and each figure (graph) a number and a title. Refer to each by number in the Results section.
14. Evaluate the hypothesis by telling if the results support or fail to support the prediction used to test the hypothesis. 
15. Address biological reasons to explain why what resulted did result, perhaps including information used to answer the questions in the lab manual.
16. State the major piece(s) of information learned in the study in a manner that has meaning if read separate from the rest of the report. 
References Cited
17. Include at least two citations. One to the lab manual, a second to the reference used to learn information related to the investigation. 


 For discussion in laboratory or in your written report.

1.   Do the results support your hypothesis?  If so, does this mean
     your hypothesis is correct? If not, might errors in the
     experimental procedure have affected the results? 

2.   Did you expect the number of mouth movements to be precisely
     the same as the number of opercular movements?  Suggest
     reasons why these values might differ.

3.   On the basis of the data obtained should the fish be
     classified as cold-blooded or warm-blooded? Does your analysis
     match that usually given in textbooks? 

4.   Did you expect that the experimental goldfish would breathe at
     the same rate as the control goldfish when they were at the
     same temperature? Suggest reasons why these values might be

5.   If a definite relationship between temperature and breathing
     was observed, suggest some reasons for this relationship. 

6.   In what way would you revise the experiment if you wished to
     test a similar hypothesis using a warm-blooded animal? Would
     you expect experimental results of such an experiment to be
     quite similar or very different?   

7.   Would the experiment have been better if we had used
     temperatures lower than 9 C and temperatures higher than 27C? 

8.   Other than an owner of a pet goldfish, who might find use for
     what was learned about breathing, temperature, and goldfish?

Guidelines for Writing Your Report - Appendix A

  As stated in Exercise 1, results of a scientific investigation
are communicated in the form of a report or  paper.   General
guidelines for writing a report of an investigative laboratory are
provided below. They should be used together with any specific
directions provided by your instructor. 

  1. Make your report an original, creative effort. Although
     you may cooperate with classmates in performing some
     experiments, the written reports which you submit should
     be written by and be original to you, and not a joint

  2. Assume that your readers will have a basic background
     knowledge of the subject matter of your investigation to
     understand and to be interested in it.

  3. Type your report on 8 X 11 in. white, opaque paper (not
     onion skin). Type on one side of the paper only. Use
     double space. Leave a 1  in. margin at the left and top,
     and a 1 in. margin at the right and bottom. Indent
     paragraphs uniformly.

  4. The first page of your report should be the title page.
     Do not number it. Center the title. Capitalize the first
     letter of the first, last, and every important word in
     the title. Do not underline the title; do not use a
     punctuation mark at the end of the title. Include on the
     title page your name, section number, date submitted, and
     any other  information in the manner prescribed by your

  5. All pages of the text of your report should be numbered
     consecutively. On the top of the first page of text
     (immediately following the title page), put the title,
     following the rules noted above.

  6. Make the title descriptive and informative so that the
     prospective reader will know the key components of your
     investigation. Normally the title will include the name
     of the organism studied, and note the biological response
     measured and major variables which were tested.

  7. Include each of the following sections in your report:

          Materials and Methods

          References Cited (The "References" section is not included in the
          body of the text, but  follows the text as the last part of the paper.)

     Use headings to identify the start of each section of the report.

  8. Introduction:

          This section provides some background information,
     placing the topic of investigation in its proper setting, and
     relating it to previously published work. If the investigation
     involves the testing of a hypothesis, that hypothesis is
     stated clearly. Included here is the basis for proposing the
     hypothesis, as well as the predicted outcome if the hypothesis
     is true. Any assumptions made in formulating the hypothesis
     are also stated.

  9. Materials and Methods: 

          Under this heading is included a description of the
     materials (for example the particular organism or tissue) to
     be used in the investigation, and of the techniques and
     procedures to be followed. This description must be
     sufficiently detailed to allow the procedure to be repeated by
     other investigators. However, if the techniques have been
     described adequately in some previous publication, a reference
     to that publication is usually sufficient. If the previously
     published techniques are to be modified in any manner, such
     modifications must be noted.

          In writing this section, state what was done. Do not
     write in the form of giving directions. Some details can be
     omitted by assuming the reader will know or presume that
     information. (For example, a reader should presume that
     temperature reported in Celsius was measured with a
     thermometer graduated in Celsius). Identify items used at the
     time that you tell how they were used. Do not list separately
     the items used.

  10. Results: 

          The data obtained from the observations are presented in
     this section. The results are usually summarized in the form
     of tables and graphs which are referenced appropriately in the
     text. The text draws attention to particular parts of the data
     presented in the tables and graphs.

     Each table and graph should:
         (a)  be included in the results section, not appended to
                 the end of the report;

          (b)  have a number (e.g., Table 1, Table 2, for tables,     
                 and Figure 1, Figure 2, for graphs);
          (c)  have a title descriptive of the information contained in it.

     In constructing your graphs:

          (a)  use this format --

          Figure 1 Format for Graphs

             high  |
Dependent          |
Variable           |
             low   |

                    low   - - - - >       high

                    Independent Variable

          (b)  identify and label the variable and the units of
                 measurement used (for  example: Temperature, oC;
                 movements per minute);

          (c)  use an appropriate scale to mark each axis of the
                 graph into proper  divisions (for example: 5 small
                 boxes = 5 degrees); different  scales may be used 
                 for the two axes. Choose a scale for each
                 axis that will spread the  points of your graph over most
                 of the paper and not crowd them into one corner.

          (d)   if several sets of data are presented on one graph,
                  use different symbols to distinguish them ( for
                  example:   -   -   -    or    .  _ . _ . _ . _   ).

  11. Discussion: 

          This part of the report includes the analysis and
  interpretation of the results. Comparisons frequently are made
  with work published previously in order to draw attention to any
  similarities or deviations. Conclusions from previous
  investigations are thus reinforced or challenged. New questions
  often are posed as a basis for future investigations. If your
  investigation involved the testing of a hypothesis, you would
  evaluate the hypothesis in the light of the data obtained.

  12. Conclusions:

           In this section, the major findings from the
  investigation are summarized in a concise statement. This
  section should be limited to one or two short paragraphs. The
  conclusions are often abstracted and thus may appear in print
  separate from the rest of the report. The title and the
  conclusions are the only parts which are read widely. Thus you
  must take care that they can be understood easily and

  13. References Cited: 

          Publications or other sources of information to which
  references are made in the report are listed at the end:

     (a)  If the reference is a journal article, use the following

          Author's last name and first initial (in the case of
          multiple authors, only the first author is listed in this
          way; the other authors are listed with initial followed
          by last name). Year of Publication. Title of article.
          Name of journal, volume and page numbers. For example: 

            Pratt, T. K. and E. W. Stiles. 1985. The influence of
            fruit size and structure on composition of frugivore
            assemblages in New Guinea. Biotropica 17:314-321

     (b)  If the reference is a book, use the following format:

          Authors' name(s) as above. Year of publication. Title of
          book. Name of publisher. Place of publication. For

            Fisher, R. A. 1930. The genetical theory of natural 
            selection.  Dover, New York.

     (c)  List references in alphabetical order (by the author's
         last name or, if the author is unknown, by the first
          significant word in the title).

     (d)  Include at least one reference, that being your
          laboratory manual. You may also refer to your text and
          perhaps one or two other books, but keep the list short.

     (e)  For examples of how references are listed, look at
          several articles in biological journals (for example,
          BioScience, American Zoologist) in the library.

  14. Have enough pride in your work to proof your report for
        spelling, grammar, punctuation, accuracy and completeness.

  15. Make a copy of your report for your records, before
         submitting the original.

  16. Fasten the pages of your report by stapling or with a

  17. Ask your instructor for help if you need clarification of
        any of the above guidelines.


The assignment for Exercise 1 is to report class data (the results from all teams) as a scientific report following the guidelines in Appendix A. The report is due at the start of the next laboratory meeting.

In addition to what is described in Appendix A, I want you to do the following:

  1. Include computer generated graphs of the class average data in the Results section of the report.
  2. Look up in some reference source information related to some aspect of the study. The reference source could be your text, an encyclopedia, a book on aquaria or tropical fish, or information from electronic sources. Include in the Introduction at least one piece of information that you learned from the reference. Cite the reference in your report.
  3. Cite in References Cited at least two sources; the reference noted above in item two, and your laboratory manual.

General Information:

The information presented here is intended to guide you as you prepare in advance of performing laboratory exercise 1, and also to help you as you write a scientific report based on the exercise.

Some instructors ask you to perform the laboratory exercise exactly as it is written and to report the results in the format described in Appendix A of the laboratory manual. However, other instructors may specify changes in the experimental design ( for example, a different number of replicate measurements, different temperatures, a particular control temperature) and / or in the nature of the assigned report. The information here is based on what Dr. Reid requires of students in the sections he teaches. If you have a different laboratory instructor, follow the directions of your instructor.

We selected this to be the first laboratory exercise because we think you will enjoy working with a familiar organism (goldfish) and watching its behaviors and activities change in response to your actions. The procedures you follow will require you to work closely with all the classmates at your table and to become an experimental team. Your team will share data with three other teams, each of which will conduct the similar experiment independently. Base your interpretation and report on the class average data (results from all four teams). In this manner you will learn if the responses of your fish are representative behaviors of goldfish or individual behaviors of the particular experimental and control goldfish that you happened to observe. We expect variability in biological data both because the fish are not identical (e.g. differences in size, age, genetic) and their treatment prior to and during the experiment.


One dictionary defines science as systematic knowledge of the physical and material world. The impact of scientific knowledge on our daily lives is obvious. In general, anything scientific almost automatically gains respectability. Results of scientific study are generally considered to be reliable. The reasons why science has become such a powerful force in human affairs are to be found in the process by which scientific knowledge is acquired. This process is called the scientific method. Its rigorous application to all scientific investigations ensures the reliability of their outcome.

The first step in any scientific inquiry is observation of objects, events and phenomena which leads to a question. This observation may be direct or indirect. In many instances, the observer may employ experimental methods to answer the question generated, that is, set up particular conditions under which additional observations will be made.

Scientists usually are interested, not merely in describing the world of nature as they find it, they are equally interested in finding explanations for natural events, processes or phenomena. Frequently, when a large number of specific observations on a given subject are made, a common pattern begins to emerge. This common pattern allows the scientist to make some generalizations about the subject of the investigation. The crucial test of whether the scientist has in fact discovered some basic natural occurrence, or some fundamental property, comes when the generalization is applied to a number of specific cases which have not been observed previously. Based on previous observations, the scientist proposes a hypothesis, which is a tentative explanation for certain phenomena or relationships. Assuming the hypothesis to be true, the scientist can then make predictions about the outcome of the proposed new observations. If the actual observations agree with the predicated ones, the hypothesis is said to be supported. If the actual observations do not agree with those predicted, the hypothesis is said to be disproved. A new hypothesis or new explanation must then be proposed and tested.

If a hypothesis is supported in a large number of specific instances, it is said to be verified. It may then lead to the establishment of a theory. A theory is a generally accepted explanation for a group of known facts or for a class of phenomena. Finally, the repeated testing of a theory might uncover some fundamental relationships which are invariable under constant conditions and therefore are predictable. A statement of such relationships constitutes a law or principle. A scientific law is universally applicable. It is, however, not absolute; it continues to be subject to testing. The results of new experiments sometimes require modifications in a supposedly well established law.

It should be noted that every scientific investigation need not incorporate all of the steps included in this scientific method. For example, many investigations are concerned only with the first step, that of observation. Such investigations are important since they contribute knowledge which leads to the formulation of generalizations. They do not, however, require the postulation of hypotheses. Other investigations involve the testing of generalizations and require construction of hypotheses based on the generalizations.

An important and essential aspect of scientific work is the communication of results of the investigation to the scientific community. This is done most commonly by publication of a formal report in a professional journal. The scientific paper, as it is called, is generally written (particularly in the biological sciences) in a standard format. General directions for writing a report are given in Appendix A of the laboratory manual.