April 2019
Intermediate to advanced
172 pages
4h 39m
Chinese
Content preview from 精通特征工程
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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.
144
｜
第
9
章
多篇论文中共有
7604
个唯一的研究领域，这些最终结果应该是向着正确方向前进。我们
的工作正逐步接近有用的模型，我们对此非常有信心。
对更多文本型变量继续迭代，比如找出论文题目中的名词短语，或对关键字进行词干提
取，都可以使我们更加接近“最佳”推荐。
需要注意的是，这里所说的“最佳”只是所有推荐器和搜索引擎追求的一种理想状态。我
们要搜索出一个对用户最有帮助的结果，这不一定能从数据中直接表现出来。特征工程可
以抽象出显著的特征并将其转化为一种表示形式，以使算法能揭示出其中包含的显式和隐
式信息。
9.5
小结
正如你看到的，建立一个机器学习模型非常容易，但要建立一个
好
模型并得到
有用
的结果
则需要花很多时间做很多工作。在本章中，我们为了获得更好的结果，检验了可能的变量
集合，使用多种特征工程方法进行了试验。在这里，“更好”的含义不仅包括从训练和测
试中得到好的结果，还包括使模型更简洁，以及减少在各种试验上的迭代时间。
本书开头说过，要精通一门学科，需要深入理解其中的原理，以便获得直觉，进而有效地
将知识应用到工作中。希望从本书中你能获得必要的方法和工具，提高工作的效率和效
果，同时扩展你的数学与计算机能力，更好地理解为什么特征工程是开发有用的机器学习
模型的一项基本技能。
9.6
参考文献
Sarwar, Badrul, George Karypis, Joseph Konstan, and John Riedl. Item-Based Collaborative
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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.
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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.