Observation
Most of the biological investigations start with an
observation. After selecting, specific biological problem, observations are
made to collect relevant information. For example; take the case of Malaria.
Malaria is the greatest killer disease of man for centuries. Malaria was one
among many other diseases for which a cure was needed.
In 1878, A French physician, Laveran, studied the blood sample of Malaria
patient under microscope and observed tiny creatures in it. These creatures
were later called Plasmodium.
Hypothesis
To solve a scientific problem, one or more possible
propositions are made on the basis of the observations. Such a proposition is
called a Hypothesis. The hypothesis is tested by scientific method.
Merits
A good hypothesis has the following merits:
1. It is close to the observed fact.
2. One or more deductions can be made from this.
3. These deductions should be confirmed doing experiments.
4. Results whether positive or negative should be reproducible.
To know the cause of malaria, following hypothesis was made:
Plasmodium is the cause of Malaria.”
Note: One or more than one possible deductions can be made from the hypothesis.
Deduction
The logical conclusion drawn from a hypothesis is
called deduction. Testing one deduction and finding it correct does not
necessarily mean the hypothesis is correct and scientific problem is solved.
Actually, if more deductions are found to be correct; the hypothesis will be
close to solution of the problem.
Experiments
Following groups are designed to perform
experiments:
Experimental Group
It is the group of those people who are affected in some way and we do not know
the real cause e.g. a group of malarial patients.
Control Group
It is the group of unaffected people e.g. persons group of healthy
persons.
By keeping both of these groups under similar conditions, the difference
between them is determined. To know the real cause of malaria, the experts
examined the blood of about 100 malarial patients (experimental group). On the
other hand, the experts examined the blood of about 100 healthy persons
(control group).
Results
During the experiments mentioned above; the
plasmodium was found in blood of most of malarial patients. The plasmodim was
absent in the blood of healthy persons. These results verified the deductions
and thus the hypothesis i.e. the plasmodium is the cause of Malaria, was proved
to a considerable extent.
Theory
If hypothesis is proved to be correct from repeated
experiments and uniform results, then this hypothesis becomes a theory.
Scientific Principle
When a theory is again and again proved to be
correct, then it is called a scientific principle.
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