Book Image

Data Science Using Python and R

By : Chantal D. Larose, Daniel T. Larose
Book Image

Data Science Using Python and R

By: Chantal D. Larose, Daniel T. Larose

Overview of this book

Data science is hot. Bloomberg named a data scientist as the ‘hottest job in America’. Python and R are the top two open-source data science tools using which you can produce hands-on solutions to real-world business problems, using state-of-the-art techniques. Each chapter in the book presents step-by-step instructions and walkthroughs for solving data science problems using Python and R. You’ll learn how to prepare data, perform exploratory data analysis, and prepare to model the data. As you progress, you’ll explore what are decision trees and how to use them. You’ll also learn about model evaluation, misclassification costs, naïve Bayes classification, and neural networks. The later chapters provide comprehensive information about clustering, regression modeling, dimension reduction, and association rules mining. The book also throws light on exciting new topics, such as random forests and general linear models. The book emphasizes data-driven error costs to enhance profitability, which avoids the common pitfalls that may cost a company millions of dollars. By the end of this book, you’ll have enough knowledge and confidence to start providing solutions to data science problems using R and Python.
Table of Contents (20 chapters)
Free Chapter
1
ABOUT THE AUTHORS
17
INDEX
18
END USER LICENSE AGREEMENT

5.2 PARTITIONING THE DATA

The Data Science Methodology does not use the statistical inference paradigm where generalization is made from a sample to a population. There are two reasons for this.

  1. Applying statistical inference to the huge sample sizes encountered in data science tends to result in statistical significance, even when the results are not of practical significance.
  2. In the statistical paradigm, the statistician has an a priori hypothesis in mind, whereas the Data Science Methodology requires no such a priori hypothesis, instead freely searching through the data for actionable results.

Because of the lack of a priori hypotheses, data scientists need to beware of data dredging, whereby phantom spurious results are uncovered, due merely to random variation rather than real effects. Data science avoids data dredging through the process of cross‐validation, a technique for ensuring that results are generalizable to an independent, unseen, data set. The most common methods...