ぎょーむ日誌 2003-10-26
2003 年 10 月 26 日 (日)
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ひさびさにやっちまった
……
ちょー時間浪費ゲイム
nethack．
ふと気づくと日の出の時間に．
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ということで
1150 起床．
でれでれとしてから昼飯．
コーヒー．
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とくに何もしてない．
あ，
北大構内走には出た．
体重 71.6kg．
あたりまえだが走ると一時的に体重おちる．
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[stats] メイリングリストで面白そうな
ワークショップの案内
来てんだよね．
11 月のは無理ってかんぢだが，
12 月のは参加できる可能性あるな．
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夜になってからメイルを片づける．
釧路大会作文問題，
いまだ片づかづ．
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[今日の素読]
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Salsburg, D. 2001.
``
The Lady Tasting Tea
-- How statistics revolutionized science
in the twentieth century''.
Owl Book.
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Chapter 17. When Part Is Better Than The Whole
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There was a basic flaw in Pearson's methods, however.
He was collecting what is now called an ``opportunity
sample.'' The data were those that were most easily
available. They did not have to be truly representative
of the entire distribution. The graves that were opened
to find the cranial capacity of skulls were those that
happened to have been found. The unfound ones could
differ in some unknown way.
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Mahalanobis resoned that it might be possible to estimate
the charachteristics of the larger population if one
could gather a small sample that was adequately
representative of the larger. At this point, we run into
two possible approaches. One is to construct what is known
``judgment sample.'' In a judgment sample, whatever is
known about the population is used to select a small
group of individuals who are chosen to represent different
groups in the larger population. The Nielsen ratings to
determine how many people are watching TV shows are
created from a judgment sample. Nielsen Media Research
selects families based on their socioeconomic status and
the region of the country in which they live.
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Mahalanobis's answer was the random sample. We use a
randomizing mechanism to pick individuals out of the
larger population. The numbers we get from this random
sample are most likely wrong, but we can use the theorems
of mathematical statistics to determine how to sample and
measure in an optimum way, making sure that, in the long
run, our numbers will be closer to the truth than any
others. Furthermore, we know the mathematical form of
the probability distribution of random samples, and we
can calcualte confidence bounds on the true values of the
things we wish to estimate.
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[今日の運動]
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北大構内走 1655-1750．
この時間はすでにまっくら．
ストレッチング．
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[今日の食卓]
- 朝 :
なんとなく食ってない
……
あ，
寝る前に少しスパゲッティー食ってしまった．
- 昼 (1230):
スパゲッティー．
トマト・タマネギ・豆腐のソース．
- 晩 (1900):
スパゲッティー．
トマト・タマネギ・豆腐のソース．