Book Image

Principles of Data Science - Third Edition

By : Sinan Ozdemir
Book Image

Principles of Data Science - Third Edition

By: Sinan Ozdemir

Overview of this book

Principles of Data Science bridges mathematics, programming, and business analysis, empowering you to confidently pose and address complex data questions and construct effective machine learning pipelines. This book will equip you with the tools to transform abstract concepts and raw statistics into actionable insights. Starting with cleaning and preparation, you’ll explore effective data mining strategies and techniques before moving on to building a holistic picture of how every piece of the data science puzzle fits together. Throughout the book, you’ll discover statistical models with which you can control and navigate even the densest or the sparsest of datasets and learn how to create powerful visualizations that communicate the stories hidden in your data. With a focus on application, this edition covers advanced transfer learning and pre-trained models for NLP and vision tasks. You’ll get to grips with advanced techniques for mitigating algorithmic bias in data as well as models and addressing model and data drift. Finally, you’ll explore medium-level data governance, including data provenance, privacy, and deletion request handling. By the end of this data science book, you'll have learned the fundamentals of computational mathematics and statistics, all while navigating the intricacies of modern ML and large pre-trained models like GPT and BERT.
Table of Contents (18 chapters)

Introduction to binary classifiers

Without getting too deep into machine learning terminology, our previous example of a cancer test is what is known as a binary classifier, which means that it is trying to predict from only two options: having cancer or not having cancer. When we are dealing with binary classifiers, we can draw what is called confusion matrices, which are 2 x 2 matrices that house all four possible outcomes of our experiment.

Let’s try some different numbers. Let’s say 165 people walked in for the study. So, our n (sample size) is 165 people. All 165 people are given the test and asked whether they have cancer (provided through various other means). The following confusion matrix shows us the results of this experiment:

Figure 5.8 – Confusion matrix

Figure 5.8 – Confusion matrix

The matrix shows that 50 people were predicted to not have cancer and did not have it, 100 people were predicted to have cancer and actually did have it, and so on...