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Unformatted text preview: st and continues with information that is progressively
more specific to the hypothesis being developed. There are two important concerns regarding
hypothesis formation. First, hypotheses need to be falsifiable with an experimental test. Second, a
workable experiment must be designed to make the test. Once a suitable hypothesis has been proposed
and an experiment designed, a prediction is made about the expected outcome of the experiment given
that the hypothesis is correct. This predictability is made possible by the deductive reasoning that was
used in the formulation of the hypothesis in concert with an awareness of the experiment that will be
performed. What is desirable here is an if/then relationship between the hypothesis and the prediction.
This is presented as follows: if the proposed hypothesis is acceptable and the experiment is performed,
then the predicted result should be attained. The experiment is then performed. If the prediction
matched the experimental result, then the hypothesis is conditionally supported in light of the
knowledge on which it was based. If the prediction did not match the experimental result, then there
was a problem with the hypothesis, the experimental approach, or both. In either case, the hypothesis
and/or the experiment should be reconsidered.
In the real world of scientific research, it is not at all unusual for predictions not to match
results in early efforts to answer a question. While this may seem discouraging to the new science
student, the positive aspect of this approach is that it represents a learning process. That is, even with
the failure of one iteration of the process, useful information has been gained for better focusing the
questions, hypotheses, experiments, and predictions for the next round which should be more
In earlier editions of your text and this lab manual, the process described above is referred to as
the “Hypothetico-Deductive (H/D)” approach to problem solving – the origin of this terminology
should be obvious from the above discussion. In Biology 5, we wish to demonstrate the practical value
of the H/D approach by expecting the student to apply it to the investigative laboratories presented in
this course. Some modifications of the procedure need to be made in order to make it applicable to
work in the teaching lab. These are the subject of the following discussion.
The H/D approach in Biology 5 laboratories.
The major differences between the form of the H/D approach used by professional researchers
and that which you will employ as beginning biology students are that the questions addressed by the
lab exercises have already been defined as have the experimental protocols used for their study. These
differences make the student’s job easier, but not trivial! Here is the amended procedure: Biology 05LA – Fall Quarter 2012 Lab 4 – page 2 1) A fundamental demand for successfully applying the H/D approach is that the student must have
attended all of the lectures associated with the lab exercise, read all of the notes taken from the
lectures, and read all of the relevant assignments in the text. This requirement is directly
comparable to the professional researcher’s need to have read all of the literature in scientific
journals that pertains to their questions.
2) Next, it is time to carefully read (and reread as necessary) the exercise in the lab manual. You then
must decide which experiments are associated with the different questions addressed by the lab
exercise (these are found either at the end of this exercise or within the relevant lab exercise).
3) Now starts the task of formulating hypotheses (or proposed answers) for the questions. This
process begins with the collection factual information relevant to the question. The sources for this
information include your lecture notes, the text, and the lab write-ups in this lab manual. The
challenge here is to organize this information deductively, that is moving in a progression from
general to specific. This step is challenging; you should see your TA for help if you are having
problems. Keep in mind that:
a) hypotheses are possible answers/explanations.
b) hypotheses reflect present knowledge about the subject area of the question.
c) hypotheses should be expressed in terms that are testable by the experiments being done. That
is, you should be able to make predictions of the outcome of your experiments given that your
hypotheses are supportable.
d) hypotheses can be eliminated but not confirmed with absolute certainty.
4) Next, you must come to understand the “experimental strategy” of the experiments you will be
performing. In other words, you need to make sure that you understand the relationship between
the data you will be collecting and the questions you are attempting to answer. In some cases, the
relationship between your data and your hypotheses will be direct and straight forward. In others,
some explanations are required to make this connection. This explanation is what we are calling
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This note was uploaded on 08/27/2013 for the course BIO BIOL05LA taught by Professor Abbottl during the Fall '12 term at UC Riverside.
- Fall '12