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

Summary

In this chapter, we learned a few techniques for interpreting machine learning models. We saw that there are techniques that are specific to the model used: coefficients for linear models and variable importance for tree-based models. There are also some methods that are model-agnostic, such as variable importance via permutation.

All these techniques are global interpreters, which look at the entire dataset and analyze the overall contribution of each variable to predictions. We can use this information not only to identify which variables have the most impact on predictions but also to shortlist them. Rather than keeping all features available from a dataset, we can just keep the ones that have a stronger influence. This can significantly reduce the computation time for training a model or calculating predictions.

We also went through a local interpreter scenario with LIME, which analyzes a single observation. It helped us to better understand the decisions made...