Thursday, August 12, 2010

Scientific Method

Science is an organized and systematic knowledge which is gathered through observations inquiry and experiments. Since function in the realm if matter and energy. The methods of science cannot be applied in areas of investigation involving the aspects of human mind and spirit. Scientific knowledge is neither inherently good nor bad. Same scientific knowledge that gave the nuclear energy and nuclear medicines also gave the nuclear wastes problems for the workers and environment.

            Make Observations
            Formulate a hypothesis
            Design a controlled experiment
            Collect data
            Interpret data
            Draw conclusions
            Consult prior knowledge

Biological method of study: In order to resolve a specific biological problem certain scientific method is adopted in which conclusion or answers to various related questions of biological problem are drawn from observation and experiments. Summary of this method is explained in the flow chart. Here malaria is being considered as an example of biological problems.
(1) Observations: After determination of specific biological problem observations are made to collect relevant information or data. Malaria is dreadful disease whose history goes back to pre birth time of Christ. In ancient days there was no treatment of malaria and large number of people used to die due to this disease. Some historians have attributed the downfall of Greek and Roman empires to this disease. The scientists were struggling to know the cure or treatment of this disease from ancient times. In those days back of cinchona tree was considered to be effective remedy against malaria. At the same time the bad air coming from stagnant ponds was considered to be possible cause of malaria. Some volunteers drank dirty water from the ponds to find the cause but failed. In 1878 French army physician Lavern found small microscope thread like organisms in the blood of malaria patients. These thread like organisms were not present in the blood of healthy person. He called this micro-organism as malarial parasite that was later described and given the name Plasmodium. By this time four major observations for malaria were recorded.
(i) Malaria and marshy places were some how associated. (ii) Quinine from cinchona bark was an effective remedy for malaria. (iii) Malaria parasites always have malarial parasite in their blood. (iv) Drinking marshy water did not cause malaria.
(2) Hypothesis: Observations alone do not usually provide solution to scientific problems. In most of the cases one or more suitable propositions are made on the basis of the observations. These propositions are called hypothesis. The hypothesis are tested by scientific method and the scientific hope that one of the hypothesis would turn out to be the solution of scientific problem under study good hypothesis has the following merits:
(i) It is close to the observed facts.
(ii) The deductions can be drawn from it.
(iii) Deduction should be suitable for testing experimentally.
(iv) Results whether positive or negative should be reproducible.
Every year about 200 million people get malaria and about two million die of it in which most of them are children and pregnant women. Main hypothesis is “Plasmodium is the cause of malaria”. Hypothesis can not be directly tested. Some deductions are made from the hypothesis which is put to test through experimentation.
(3) Deduction: Many deductions may be drawn from hypothesis. Testing one deduction and finding it correct does not mean the hypothesis is correct. The validity of hypothesis is more supported if many deductions confirm the hypothesis. Symptoms of deductions are (i) High fever (106°F) with shivering (ii) Headache and nausea (iii) High breathing rate with increased heart beat (iv) Heavy sweating sometime after high fever leading to normal or below normal temperature (v) Person feels fatigued and exhausted (vi) Recurrence of all above symptoms after specific intervals in absence of proper treatment. Deduction can be tested by experiment.
(4) Experiment: Experimental group is the group of those people who are affected but the real cause is now known e.g. group of malarial patient on the other hand a group of un affected people is called control group e.g. group of healthy people. Both groups are kept in identical conditions. In order to find out the real cause of malaria, experts examined the blood of about 100 malaria patients termed as experimental group, and examined blood of 100 healthy persons known as control group.
(5) Results: Most of the malarial patients had plasmodium in their blood where as the blood of healthy persons was free of plasmodium. These results verified the deduction and thus the hypothesis i.e. the plasmodium is the cause of malaria was proved to great extent. AF. A King in 1883 suggested “Mosquitoes are involved in spreading the malaria”. His observations are (i) People who slept out doors in open spaces suffered more frequently from malaria than those who slept indoors (ii) People who slept under mosquito net did not suffer from malaria. (iii) Persons who slept near smoke fire also did not suffer from malaria.
Opinions of King were further tested by Ronald Ross in 1880 who performed different experiments in order to establish relationship between the work of Lavern and King. After discovery that plasmodium is the cause of malaria, Ronald Ross tried to find out how plasmodium entered the blood of man. He observed that plasmodium was growing and multiplying in the stomach of female. Anopheles mosquito that had bitten a person ill with malaria Ross selected sparrow instead of man for experiments. Malarial parasite (plasmodium) completes its life cycle in two steps. Asexual reproduction is completed in human body and sexual reproduction completed in the body of female Anopheles mosquito. Ross proved that mosquito is the cause of malaria that transferred plasmodium from the blood of one sparrow to the other.

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2 Responses to “Scientific Method”

Anonymous said...
March 10, 2012 at 1:17 AM

nicely described and it helped me alot
(*u*)....thanks


Anonymous said...
March 3, 2015 at 9:57 PM

it helps me alot


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