Book Image

The Data Science Workshop - Second Edition

By : Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare
5 (1)
Book Image

The Data Science Workshop - Second Edition

5 (1)
By: Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare

Overview of this book

Where there’s data, there’s insight. With so much data being generated, there is immense scope to extract meaningful information that’ll boost business productivity and profitability. By learning to convert raw data into game-changing insights, you’ll open new career paths and opportunities. The Data Science Workshop begins by introducing different types of projects and showing you how to incorporate machine learning algorithms in them. You’ll learn to select a relevant metric and even assess the performance of your model. To tune the hyperparameters of an algorithm and improve its accuracy, you’ll get hands-on with approaches such as grid search and random search. Next, you’ll learn dimensionality reduction techniques to easily handle many variables at once, before exploring how to use model ensembling techniques and create new features to enhance model performance. In a bid to help you automatically create new features that improve your model, the book demonstrates how to use the automated feature engineering tool. You’ll also understand how to use the orchestration and scheduling workflow to deploy machine learning models in batch. By the end of this book, you’ll have the skills to start working on data science projects confidently. By the end of this book, you’ll have the skills to start working on data science projects confidently.
Table of Contents (16 chapters)
Preface
12
12. Feature Engineering

Introduction

In the previous chapter, Chapter 12, Feature Engineering, where we dealt with data points related to dates, we were addressing scenarios pertaining to features. In this chapter, we will deal with scenarios where the proportions of examples in the overall dataset pose challenges.

Let's revisit the dataset we dealt with in Chapter 3, Binary Classification, in which the examples pertaining to 'No' for term deposits far outnumbered the ones with 'Yes' with a ratio of 88% to 12%. We also determined that one reason for suboptimal results with a logistic regression model on that dataset was the skewed proportion of examples. Datasets like the one we analyzed in Chapter 3, Binary Classification, which are called imbalanced datasets, are very common in real-world use cases.

Some of the use cases where we encounter imbalanced datasets include the following:

  • Fraud detection for credit cards or insurance claims
  • Medical diagnoses where we...