每日一练 | Data Scientist & Business Analyst 面试题 151

大数据应用 · 公众号 · 大数据 · 2017-08-05 09:15

正文

从6月15日起，数据应用学院将与你一起温习数据科学（DS）和商业分析（BA）领域常见的面试问题。希望积极寻求相关领域工作的你每天关注我们的问题并且与我们一起思考，我们将会在第二天给出答案。

Day 51

DS Interview Questions

What are the primary differences & similarity between classification and regression trees.

BA Interview Questions

R language:

Using the following variables:

x=1

y=40

i=c(1:10)

## write a for() loop that increments x by three and decrease y by two, for each i.

欲知答案如何？请见下期分解！

Day 50 答案揭晓

DS Interview Questions

What’s the advantages and disadvantages of decision tree.

Advantage:
Easy to Understand: Decision tree output is very easy to understand. Its graphical representation is very intuitive and users can easily relate their hypothesis.
Useful in Data exploration: Decision tree is one of the fastest way to identify most significant variables and relation between two or more variables. With the help of decision trees, we can create new variables / features that has better power to predict target variable. It can also be used in data exploration stage. For example, we are working on a problem where we have information available in hundreds of variables, there decision tree will help to identify most significant variable.
Less data cleaning required: It requires less data cleaning compared to some other modeling techniques. It is not influenced by outliers and missing values to a fair degree.
Data type is not a constraint: It can handle both numerical and categorical variables.
Non Parametric Method: Decision tree is considered to be a non-parametric method. This means that decision trees have no assumptions about the space distribution and the classifier structure.

Disadvantages:
Overfitting: Overfitting is one of the most practical difficulty for decision tree models. This problem gets solved by setting constraints on model parameters and pruning.
Not fit for continuous variables: While working with continuous numerical variables, decision tree looses information when it categorizes variables in different categories.

BA Interview Questions

R language:

Using the following variables:

x=1

i=c(1:10)

## write a for() loop that increments x by two for each i

for(j in i){
x=x+2
print(x)
}

数据应用学院

数据应用学院（Data Application Lab）, 北美第一家培训－项目实习－职业辅导－内推一站式专业数据人才输送机构，提供大数据和数据科学培训和公司项目解决方案，由南加州与硅谷的高级数据科学家与数据工程师联合创办，致力于传播数据行业最新应用和知识、培训及输送优秀大数据人才，以填补人才缺口、充分发挥大数据在商业中的力量。2016年被北美著名科技杂志Tech Beacon评为Top Data Camp。

长期招募

TECHNICAL WRITER/翻译志愿者

职责：

深度讨论数据应用
调研行业发展

要求：

对数据应用极为感兴趣
具备数据分析基础
具有一定BUSINESS INSIGHT
写作能力强

感兴趣的同学发送简历及writing sample到[email protected]，邮件标题“申请翻译/Technical Writer”。

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