Book Image

Essential Statistics for Non-STEM Data Analysts

By : Rongpeng Li
Book Image

Essential Statistics for Non-STEM Data Analysts

By: Rongpeng Li

Overview of this book

Statistics remain the backbone of modern analysis tasks, helping you to interpret the results produced by data science pipelines. This book is a detailed guide covering the math and various statistical methods required for undertaking data science tasks. The book starts by showing you how to preprocess data and inspect distributions and correlations from a statistical perspective. You’ll then get to grips with the fundamentals of statistical analysis and apply its concepts to real-world datasets. As you advance, you’ll find out how statistical concepts emerge from different stages of data science pipelines, understand the summary of datasets in the language of statistics, and use it to build a solid foundation for robust data products such as explanatory models and predictive models. Once you’ve uncovered the working mechanism of data science algorithms, you’ll cover essential concepts for efficient data collection, cleaning, mining, visualization, and analysis. Finally, you’ll implement statistical methods in key machine learning tasks such as classification, regression, tree-based methods, and ensemble learning. By the end of this Essential Statistics for Non-STEM Data Analysts book, you’ll have learned how to build and present a self-contained, statistics-backed data product to meet your business goals.
Table of Contents (19 chapters)
1
Section 1: Getting Started with Statistics for Data Science
5
Section 2: Essentials of Statistical Analysis
10
Section 3: Statistics for Machine Learning
15
Section 4: Appendix

Overviewing tree-based methods for classification tasks

Tree-based methods have two major varieties: classification trees and regression trees. A classification tree predicts categorical outcomes from a finite set of possibilities, while a regression tree predicts numerical outcomes. Let's first look at the classification tree, especially the quality that makes it more popular and easy to use compared to other classification methods, such as the simple logistic regression classifier and the naïve Bayes classifier.

A classification tree creates a set of rules and partitions the data into various subspaces in the feature space (or feature domain) in an optimal way.

First question, what is a feature space?

Let's take our stroke risk data that we used in Chapter 9, Statistics for Classification, as sample data. Here's the dataset from the previous chapter for your reference. Each row is a profile for a patient that records their weight, diet habit, smoking...