Book Image

Regression Analysis with R

By : Giuseppe Ciaburro
Book Image

Regression Analysis with R

By: Giuseppe Ciaburro

Overview of this book

Regression analysis is a statistical process which enables prediction of relationships between variables. The predictions are based on the casual effect of one variable upon another. Regression techniques for modeling and analyzing are employed on large set of data in order to reveal hidden relationship among the variables. This book will give you a rundown explaining what regression analysis is, explaining you the process from scratch. The first few chapters give an understanding of what the different types of learning are – supervised and unsupervised, how these learnings differ from each other. We then move to covering the supervised learning in details covering the various aspects of regression analysis. The outline of chapters are arranged in a way that gives a feel of all the steps covered in a data science process – loading the training dataset, handling missing values, EDA on the dataset, transformations and feature engineering, model building, assessing the model fitting and performance, and finally making predictions on unseen datasets. Each chapter starts with explaining the theoretical concepts and once the reader gets comfortable with the theory, we move to the practical examples to support the understanding. The practical examples are illustrated using R code including the different packages in R such as R Stats, Caret and so on. Each chapter is a mix of theory and practical examples. By the end of this book you will know all the concepts and pain-points related to regression analysis, and you will be able to implement your learning in your projects.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Chapter 6. Avoiding Overfitting Problems - Achieving Generalization

In the previous chapters, we have emphasized the importance of the training phase for successful modeling. In the training phase, the model is developed by accurately specifying the level of detail that the system will be able to predict. The higher the degree of detail required, the greater the ability to predict from the model. So far, nothing strange has been found. Problems arise when we use that model to make new predictions based on data that the model does not know. The risk we run is that we push the precision in the details so much that we lose the ability to generalize.

Let's consider a practical example: suppose we build a face recognition model. Since each pixel can be compared between one image and the other, it may happen that minor details become overwhelming: hair, background, shirt color, and so on. The number of details on which the model can play is so wide that it is able to identify individual images...