Science can be considered as both a body of knowledge and a process of
acquiring new knowledge about the physical and natural world. Formulation of
new theories in science, debunking or superseding theories can be possible
outcomes of acquisition new knowledge from successful scientific inquiry. Such
occurrences where refutation of theories put forward by many famous scientists
were evident in the past years.
Scientific inquiry refers to diverse ways in which scientists study
the natural world and propose explanations based on the evidence derived from
their work. It consists of ordered steps to be followed when formulating new theories.
The ordered steps of scientific inquiry are as follows.
1. Identification of the problem
2. Observation
3.Formulating hypotheses based on the observations
4. Test hypothesis
5. Analyze results
6. Draw a conclusion
Scientific inquiry generally aims to obtain knowledge in the form of
testable explanations that scientists can use to predict the results of the
future experiments.
How is a hypothesis formulated? Can we make hypotheses as we wish?
The
answer is certainly no, because hypothesis will be the determining factor to
make investigations a success .So, we must carefully formulate hypothesis. The hypotheses must be almost all possible
suggested explanations for the problem. There may be thousands of hypotheses but only a few would support the problem as
per the results of hypothesis testing.
Hypothesis Testing
Formulated hypothesis must be tested for its confirmation to proceed with
the scientific inquiry. There are several possible ways to test a hypothesis
and it depends on the nature of the hypothesis.
- Some hypotheses can be
direct which means that those hypotheses contain readily available facts with evidences
and where special experimentations are not required.
- But most often the hypotheses
are not direct and thereby, require carefully planned tests to obtain more accurate
results .
For example, during the outbreak of cholera disease in the mid-19th
century many scientists and doctors came up with possible hypotheses for the
cause for cholera disease. William Farr investigated this problem to see
whether cholera was caused by miasmata. He formulated the hypothesis with
the test implication as follows. If cholera disease is caused by inhalation of
miasmata, then first symptoms of the patients must appear in the respiratory
tract. So he carried out a survey examining the first symptoms of patients to
confirm the test implication. However, the test implication failed as the
statistically reported results failed to prove the hypothesis. The test results showed that first symptoms of most patients
were associated with the digestive tract.
The above mentioned hypothesis can also
be logically tested as given below.
The above argument is a deductively valid with the logical form of modus
tollens and it supports the hypothesis with certainty.
In developing such
arguments deductive reasoning is more preferred than inductive reasoning.
However ,hypothesis with inductive logic can neither be neglected. Consider the following argument.
Here the argument presented is in incorrect logical form which is incorrect use of modus ponens. Even though the argument presented is invalid it still can have inductive strength and at such instances experiments
performed fails to reject the hypothesis. Therefore, scientists must be very careful when
formulating ,testing and confirming a hypothesis .
Confirming a Hypothesis
Not all hypothesis can be conclusively proved even when their
experiments are extensive ones with favourable outcomes. Scientific acceptability of a hypothesis certainly depends on the :
relevance,
extent
and
strength of the available evidence .
The test variety used in confirming the hypothesis is another factor which at most times help in establishing strong proof . Considering the cause of cholera disease if he used several other criteria in
testing the hypothesis such as whether there was an effect from the food consumed
or water consumed then according to the diversified evidences he will be able
to strongly prove the hypothesis and interrelate them in a scientific way. But
not all diversified evidences will conclusively support a hypothesis.
Thus, the person who performs the tests must have clear knowledge about the
subject and limitations in work.
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