Coursera 吴恩达Machine Learning(机器学习)课程 |第一周测验答案(仅供参考)

注：每个人的题目和选项并不完全一样，但大部分题目的大致意思相同。

一、Introduction

1.A computer program is said to learn from experience E with respect to some task T and some performance measure P if its performance on T, as measured by P, improves with experience E. Suppose we feed a learning algorithm a lot of historical weather data, and have it learn to predict weather. In this setting, what is T?如果一个计算机程序在T上的表现（用P衡量）随着经验E的提高而提高，那么它就可以从经验E中学习关于某个任务T和某个性能度量P的知识。假设我们给一个学习算法输入大量的历史天气数据，让它学习预测天气。在这种情况下，T是什么？

• A.None of these. 这些都不是。
• B.The process of the algorithm examining a large amount of historical weather data. 算法对大量历史气象数据进行检验的过程。
• C.The probability of it correctly predicting a future date’s weather.The probability of it correctly predicting a future date’s weather. 它正确预测未来天气的概率。
• D.The weather prediction task. 天气预报任务。

2.Suppose you are working on weather prediction, and use a learning algorithm to predict tomorrow’s temperature (in degrees Centigrade/Fahrenheit). Would you treat this as a classification or a regression problem?假设您正在进行天气预报，并使用学习算法预测明天的温度（摄氏度/华氏度）。你认为这是分类问题还是回归问题？

• A.Classification 分类
• B.Regression 回归

3.Suppose you are working on stock market prediction, and you would like to predict the price of a particular stock tomorrow (measured in dollars). You want to use a learning algorithm for this. Would you treat this as a classification or a regression problem?假设你正在做股票市场预测，你想预测明天某只股票的价格（以美元为单位）。你想为此使用一个学习算法。你认为这是分类问题还是回归问题？

• A.Classification 分类
• B.Regression 回归

4.Some of the problems below are best addressed using a supervised learning algorithm, and the others with an unsupervised learning algorithm. Which of the following would you apply supervised learning to? (Select all that apply.) In each case, assume some appropriate dataset is available for your algorithm to learn from.下面的一些问题最好用有监督的学习算法来解决，而另一些问题则用无监督的学习算法来解决。你会将监督学习应用于以下哪一项(在每种情况下，假设有合适的数据集可供算法学习。

• A.Have a computer examine an audio clip of a piece of music, and classify whether or not there are vocals (i.e., a human voice singing) in that audio clip, or if it is a clip of only musical instruments (and no vocals). 让计算机检查一段音乐的音频剪辑，并对该音频剪辑中是否有人声（即人声演唱）或是否只有乐器的剪辑（没有人声）进行分类。
• B.Given genetic (DNA) data from a person, predict the odds of him/her developing diabetes over the next 10 years. 根据一个人的基因（DNA）数据，预测他/她在未来10年患糖尿病的几率。
• C.Given data on how 1000 medical patients respond to an experimental drug (such as effectiveness of the treatment, side effects, etc.), discover whether there are different categories or “types” of patients in terms of how they respond to the drug, and if so what these categories are. 给出1000名医疗患者对实验药物的反应（如治疗效果、副作用等）的数据，找出是否有不同类别或“类型”的患者对药物的反应，如果有，这些类别是什么。
• D.Given a large dataset of medical records from patients suffering from heart disease, try to learn whether there might be different clusters of such patients for which we might tailor separate treatments. 考虑到一个来自心脏病患者的大量医疗记录数据集，试着了解是否可能存在不同的此类患者群，我们可以为这些患者量身定制不同的治疗方法。

5.Which of these is a reasonable definition of machine learning? 以下哪项是机器学习的合理定义？

• A.Machine learning learns from labeled data. 机器学习从标记数据中学习。
• B.Machine learning is the field of study that gives computers the ability to learn without being explicitly programmed. 机器学习是一个研究领域，它使计算机能够在没有明确编程的情况下进行学习。
• C.Machine learning is the science of programming computers. 机器学习是计算机编程的科学。
• D.Machine learning is the field of allowing robots to act intelligently. 机器学习是允许机器人智能行动的领域。
  
  上述答案均正确
  

二、Linear Regression with One Variable

注意：这里的第五题并不一定是多选。

以上答案均正确。

三、Linear Algebra

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翻译来自百度翻译。答案是我自己做的，仅供参考。