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Statistics as a Key Technology in
Real Life Applications
y A talk by
Professor S. K. Neogy
Indian Statistical Institute Delhi Centre
On
World Statistics Day at Ramjas College, University of Delhi
October 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
y 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.
y The early statistical studies included analyses of data on stature of
Anglo-Indians, meteorological data, rainfall data, data on soil
conditions, etc.
y 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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The Statistical Mind
y 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.
y 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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The Statistical Mind
y 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 methodology
which 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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Misconceptions 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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Salt in statistics……..
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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Salt in statistics……..
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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Salt in statistics……..
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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Salt in statistics……..
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.
y Statistics prove that cigarette smoking is bad.
y According to statistics, males who remain unmarried
die ten years younger.
y Statistically speaking tall parents have tall children.
y 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 ……..
y Statistics confirm that an intake of 500 mg of vitamin
C every day prolongs life by six years.
y 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:
y All work occurs in a system of interconnected processes
y Variation exists in all processes, and
y Understanding and reducing variation are keys to
success and improves quality of Life.
y 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…….
y In the past, the economy of a country depended on
how well it was preparing for war.
y 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 …….
y Our success will depend on acquiring and processing
the information needed for optimum decision making
by 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…….
y In achieving this revolution,
Statistics would be the key technology,
a technology for shaping a new world through
peace.
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References:
y P. C. Mahalanobis, Statistics as a Key Technology, The
American Statistician, Vol. 19, No. 2 (Apr., 1965), pp. 43-46
y C. R. Rao, STATISTICS AND TRUTH Putting Chance
to Work (2nd ed.), World Scientific, 1997.
y Richard Von Mises, Probability, statistics, and truth, Courier
Dover Publications, 1981