Wednesday, June 5, 2013

Left-handed Coconut Trees and Other Statistical Tales

Lots of more interesting stuff in C. R. Rao's 1989 lecture. I blogged about a historically interesting demand estimation problem from this talk earlier today. I'm sharing other comments below. Italicized words are mine.

On the philosopher's view of knowledge.
...Vivekananda and Einstein maintained that new knowledge can be created only by instinct, reason and inspiration, a process known as abduction and not by deductive reasoning assuming a given set of premises to be true or by inductive inference from observed data. ( “a theory can be proved by an experiment, but no path leads from experiment to theory”-Einstein).

The ancient Hindu scriptures mention, perception (pratyksha), inference (anumana), comparison (upamana) and verbal testimony (sabda) as possible instruments for creation of new knowledge.

From a subsection on the scientist's view of knowledge
"In May 1983, exactly 350 years after Galileo‟s confession, Pope John Paul II graciously conceded to a delegation of 200 scientists that the Pope Urban VIII who convicted Galileo might have erred. In July 1984, after examining all the relevant documents, Pope Paul II exonerated Galileo saying that the judges who condemned Galileo were wrong."

On Serendipity in scientific discoveries
"Pluto's moon Charon was discovered by US astronomer James Christy in 1978. He was going to discard what he thought was a defective photographic plate of Pluto, when his Star Scan machine broke down. While it was being repaired he had time to study the plate again and discovered others in the archives with the same "defect" (a bulge in the planet's image which was actually a large moon)."
One person's discarded 'outlier' is another person's treasure.

On statistics and scientific research.
... As R.A.Fisher said in a speech delivered at the Indian Statistical Institute in 1952: “Statistical science is the peculiar aspect of human progress which gave 20th
century its special character. It is to the statistician the present age turns for
what is most essential in all its more important activities”."
perhaps he meant to say 'Operations Research'. maybe not.

R.A.Fisher. Emphasizing the need for consulting a statistician before the experiment is conducted, Fisher said:
“You get 10 times more information from a carefully designed experiment. To consult a statistician after the experiment is finished is often to merely ask him to conduct a postmortem examination. He can only say what the experiment died of”.

“Statistics is the technology of finding the invisible and measuring the immeasurable”.

On statistical applications.
"....Galton was able to collect birth order data from 99 of his [gifted, accomplished] subjects, revealing that 48% of them were first born sons or only sons. The percentages of the second and third born were very low..."
Rao mentions he was his parent's eighth child.

...T.A. Davis, a professor at the Indian Statistical Institute made several studies on coconut trees which can be classified as left-handed or right- handed depending on the direction of its foliar spiral. By doing experiments he found that spirality is not genetically inherited and left handed trees yield 10% more coconuts than the right handed trees, a conclusion of economic importance. A recommendation was made to the Government in the state of Kerala to grow only the” leftists to increase the production of nuts”.
Possible context: Kerala was crazy enough to willfully usher in the world's first democratically elected communist government.

On facts before theory:
“It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories instead of theories to suit facts.
- Sherlock Holmes

Without good information, you won‟t see things as they really are-you will see them as you think they are.
“Aristotle maintained that women have fewer teeth than men; although he was married twice, it never occurred to him to verify his statement by examining his wives ‟mouth”.
- Bertrand Russel

On decision making under uncertainty, an important area of ORMS.
“The need for knowing the three R’s, reading, writing and arithmetic, is well understood. These do not take us far unless we acquire the fourth R, reasoning under uncertainty, for taking decisions in real life”.
-C.R.Rao (Statistics and Truth)

Rao finishes with this.
The philosopher Sullivan, when asked whether he believes in astrology, replied.
“I am a Gemini and Gemini do not believe in astrology”.
Thank you.

updated: June 6, typos.


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