July 2014
Beginner to intermediate
456 pages
11h 26m
Japanese
Content preview from 戦略的データサイエンス入門 ―ビジネスに活かすコンセプトとテクニック
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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.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.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.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.
80
3 章 予測モデリング：相関から教師ありセグメンテーションへ
ルールが出来上がります。こうしてできるルールは、属性の評価条件を「かつ（
AND
）」 で
つなげたものになります。図
3-15
で、ルートノードから始めて、いつも左側のブランチを
選んでいくとしましょう。こうすると次のルールが出来上がります。
(
残高
< 50K)
かつ
(
年齢
< 50)
ならば、クラス
=
回収不能
このようにして他のすべてのリーフに達する経路を考えると、さらに次の
3
つのルールが
得られます。
(
残高
< 50K)
かつ
(
年齢
≥ 50)
ならば、
クラス
=
回収不能でない
(
残高
≥ 50K)
かつ
(
年齢
< 45)
ならば、
クラス
=
回収不能
(
残高
≥ 50K)
かつ
(
年齢
≥ 45)
ならば、
クラス
=
回収不能でない
図
3-15
の分類木はこのルールのセットと等しいのです。このルールは同じような条件の
繰り返しを集めたように見えるかもしれませんが、それはたまたまこの分類木がそのような
構成になっているからです。すべての分類木はこのようにルールのセットとして表すことも
できます。分類木かルールのセットのどちらがわかりやすいかは、その状況と見る人によっ
て異なります。今見たような簡単な例では、どちらもわかりやすいですが、モデルが大きく
なっていくと、人によって意見が分かれます。
3.5
確率推定
たいていの場合、意思決定をするための問題では、単なる分類ではなく、より意味がある
情報を得られる予測をしたいものです。例えばこれまでに見てきた他社への乗り換え予測問 ...
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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.