September 2014
Intermediate to advanced
236 pages
4h 17m
Japanese
Content preview from Think Bayes ―プログラマのためのベイズ統計入門
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142
■
12
章
証拠
すべての問題が同じ程度に難しいというモデルを選んだならば、各受験者について
特性
p_correct
を定義できる。これは、問題に正しく答えられる確率である。この単純
化は、与えられた得点の尤度の計算をやさしくする。
12.2
スケール
SAT
の点数を理解するには、点数付けとスケール合わせの処理過程を理解しなけれ
ばならない。各受験者は、正答と誤答の個数に基づいて基本的な点数を得る。基本点
数は、
200-800
という範囲のスケールに合わせた得点に変換される。
2009
年には、数学の
SAT
には、
54
の問題があった。各受験者の基本点数は、正答
数から誤答数の
1/4
を差し引いたものである。
SAT
を管理している大学理事会（
College Board
）は、基本得点からスケール化得点へ
の変換表を公表している。私はそのデータをダウンロードして、それを
Interpolater
（内挿）オブジェクトにラップして、前方（基本からスケール化）後方（スケール化から基
本）と表引きができるようにした。
この例題のコードは、
http://thinkbayes.com/sat.py
からダウンロードできる。詳細に
ついては、まえがきの「コードについて」（
ix
ページ）を参照のこと
12.3
事前確率
大学理事会は、すべての受験者のスケール化得点の分布も公表している。スケール
化得点を基本得点に変換して、問題数で割れば、結果が
p_correct
の推定となる。そ
こで、基本得点の分布を使って、
p_correct
の事前確率
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.