What is meant by scientific method?

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Scientific method is a specific way of "doing science". As described in a number of textbooks, this involves a progression of steps employing both inductive and deductive reasoning, as follows:
    1. making an observation of some phenomenon
    2. proposing a hypothesis to explain it
    3. designing an experiment to test this, together with logical predictions
    4. performing the experiment
    5. analysing the results
    6. drawing conclusions re the validity of the original hypothesis
    7. reformulating the hypothesis
    8. further experimenting, until
    9. reaching confidence about the validity of your hypothesis as an adequate explanation of your data
    Physiology is almost entirely an experimentally-based discipline, with information being gathered both from observations on what goes wrong in ill-health and from controlled experiments using either animals or humans. One aphorism which you may find useful is "Facts ain’t given, they’re gotten". In other words, circumstances have to be actively structured in such a way that valid and reliable observations can be made of whatever phenomena are of interest.

    The most important learning step which occurs is when observed results are compared to those predicted, and any discrepancies which are found need to be explained. It is then that the experimenter realizes that there must have been certain variables which were not controlled, and which influenced the outcome in an unexpected manner This then results in a better designed experiment (see below). The inherent variability in the biological sciences cannot be over-emphasized, and is something of which you must always be aware.

    Whenever you perform an experiment in a practical class, you will be employing some of the steps in the sequence above. In order to help you develop the skills necessary for this process your second year practicals have been broken down into a series of exercises, as under the headings which follow.


    The first important point is that a scientific experiment must be grounded in a theoretical framework, unless one is breaking completely new ground, i.e. your hypothesis must be formulated from some knowledge base. In your practical course your first task will be to complete a pre-test or preparatory exercise covering the theoretical concepts which are essential for your understanding of what you will do in the laboratory. You will need to read your practical notes carefully beforehand, especially the Introduction, so as to establish which topic areas from your lecture material are relevant and form the theoretical background. You may also need to revise basic scientific or mathematical concepts from your earlier studies. An example of a typical question is given below; it is taken from a practical on the effects of thyroid hormones:

    What is the effect of thyroid hormone on basal metabolic rate, and how might this be manifested in relation to body temperature, appetite and body weight?

    Programmed Text

    This is another learning aid which can be used to cover background material. As an example of such texts you should work through the model How to Use a Programmed Text (see Appendix A), before attempting the one which is relevant to the particular practical.

    Practical Objectives

    Even though you will not always have the opportunity to design your own experiments, you need to be aware of the reasoning behind the ones in your books. Each class has both a General Objective, or overall aim, which is equivalent to the main hypothesis which you are going to test. Each class also has a number of Specific Objectives, which detail different aspects of that hypothesis, the various logical predictions from it, which underpin the experiments. In some practicals you can add to this list with your own hypotheses, and if time permits, actually carry out the experiments to test them.

    Experimental Method, Results and Discussionsections will be discussed later.

    The Background information on practicals summary in Part II of the second year course guide is a useful comparison of the features of different practicals.

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