Wsdrajtalk202010

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Statistics as a Key Technology in Real Life Applications

❖ A talk byProfessor S. K. Neogy

Indian Statistical Institute Delhi CentreOn

World Statistics Day at Ramjas College, University of DelhiOctober 20, 2010

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The Statistical Mind

Statistics as a Key Technology

Prof. P. C. Mahalanobis

Founder, Indian Statistical Institute

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Recognition of Statistics as a Key Discipline in India

❖ During the 1920s and until the mid-1930s, all or nearly all the statistical work done in India, was done single-handedly by Prof. Mahalanobis.

❖ The early statistical studies included analyses of data on stature of Anglo-Indians, meteorological data, rainfall data, data on soil conditions, etc.

❖ Some of the findings of these early studies were of great impact in the control of floods, development of agriculture, etc., and led to the recognition of Statistics as a key discipline.

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❖ Mahalanobis' influence was so pervasive that students of Physics began to take interest in Statistics. Several talented young scholars including J.M. Sengupta, H.C. Sinha, R.C. Bose, S.N. Roy, K.R. Nair, K. Kishen and C.R. Rao, joined to form an active group of statisticians.

❖ Mahalanobis continued to be the nucleus. Theoretical research in Statistics began to flourish in the Institute. Research on large scale sample surveys won Mahalanobis a Fellowship of the Royal Society. Design and analysis of agricultural experiments also bloomed and led to some international contacts, notably with Sir Ronald A. Fisher.

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❖ What began as a small room in the Presidency College with a total

annual expenditure of less than Rs. 250 in 1931, now comprises

buildings on several acres of land in four major cities (Calcutta, New

Delhi, Bangalore and Hyderabad)!

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Statistics :Science, technology or art ……..

1. Is statistics, as studied and practiced today, a science, technology or art?

2. Perhaps it is a combination of all these.

3. It is a science in the sense that it has an identity of its own with a large of techniques derived from some basic principles.

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Statistics……..

4. It is a technology in the sense that statistical methodology can be built into any operating system to maintain a desired level and stability of performance

5. Statistics is also an art, because its methodologywhich depends on inductive reasoning is not fully codified or free from controversies.

6. Skill and experience of a statistician, which makes statistics an art.

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Future of Statistics……..

What is the future of statistics?

1. Statistics is now evolving as a meta-science.

2. Its object is the logic and the methodology of other sciences - the logic of decision making and the logic of experimenting in them.

3. The future of statistics lies in the proper communication of statistical ideas to research workers in other branches of learning.

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M isconceptions and skepticisms about statistics ……..

A health minister was looking at the statement in the report submitted by a statistician that 3.2 persons out of 1000 suffering from a disease died during the last year.

He asked his private secretary, an administrator, how 3.2 persons can die. The secretary replied,

Sir, when a statistician says 3.2 persons died, he means that 3 persons actually died and 2 are at the point of death.

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Spreading statistical numeracy ……..

We learn the 3 R’s in the school - reading, writing and

arithmetic. These are not sufficient.

There is a greater need to know how to handle uncertain situations.

How do we take a decision when there is insufficient information?

Attempts should be made to introduce the fourth R,reasoning under uncertainty, in the school curriculum at an early stage.

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Salt in statistics……..

There were communal riots in Delhi in 1947 immediately after India achieved independence.

A large number of people of a minority community took refuge in the Red Fort which is a protected area

The Government had the responsibility to feed these refugees

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Then the problem before the experts was

to estimate the number of persons inside a given area

without any prior information about the order of magnitude of the number,

without having any opportunity to look at the concentrations of persons inside the area and without using any known sampling techniques for estimation or census methods.

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Available data:

Bills submitted by the contractors to the government, which gave the quantities of various commodities such as rice, pulses and salt purchased by them to feed the refugees.

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Let R, P and S represent the quantities of rice, pulses and salt

used per day to feed all the refugees.

From consumption surveys, the per capita requirements of these commodities are known, say, r, p and s respectively.

Then R/r, P/p and S/s would provide parallel (equally valid) estimates of the same number of persons.

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It was found that

S/s had the smallest value and

R/r, the largest value indicating that the quantity of rice,

which is the most expensive commodity compared to salt, was probably exaggerated.

The estimate S/s was proposed by the statisticians for the number of refugees in the Red Fort.

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Statistics: a magic word ……..

Now statistics has become a magic word to give a semblance of reality to statements we make.

❖ Statistics prove that cigarette smoking is bad.

❖ According to statistics, males who remain unmarried die ten years younger.

❖ Statistically speaking tall parents have tall children.

❖ A statistical survey has revealed that a tablet of aspirin every alternate day reduces the risk of a second heart attack.

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Statistics: a magic word ……..

❖ Statistics confirm that an intake of 500 mg of vitamin C every day prolongs life by six years.

❖ A statistical survey has revealed that henpecked husbands have a greater chance of getting a heart attack.

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Statistical Thinking & Quality of Life……..

Statistical Thinking is a philosophy of learning and action based on the following fundamental principles:

❖ All work occurs in a system of interconnected processes

❖ Variation exists in all processes, and

❖ Understanding and reducing variation are keys to success and improves quality of Life.

❖ Statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write

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Statistical concepts and methods can play an important role in resolving complex issues involved in civil cases like disputed paternity, alleged discrimination against minority groups in employment opportunities,and consumer protection against misleading advertisements.

In all such cases, the arguments can be based on statistical data and their interpretation.

Statistics and the Law……..

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Past, Present and Future…….

❖ In the past, the economy of a country depended on how well it was preparing for war.

❖ The biggest problem of the coming decades for any country is not the challenge of war but of peace.

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Our success …….

❖ Our success will depend on acquiring and processing the information needed for optimum decision makingby which the available resources, both in men and material, are put to maximum use for improving the quality of life of individuals.

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Finally…….

❖ In achieving this revolution,

Statistics would be the key technology,

a technology for shaping a new world through peace.

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References:

❖ P. C. Mahalanobis, Statistics as a Key Technology, The

American Statistician, Vol. 19, No. 2 (Apr., 1965), pp. 43-46

❖ C. R. Rao, STATISTICS AND TRUTH Putting Chance

to Work (2nd ed.), World Scientific, 1997.

❖ Richard Von Mises, Probability, statistics, and truth, Courier

Dover Publications, 1981