Book Image

The Supervised Learning Workshop - Second Edition

By : Blaine Bateman, Ashish Ranjan Jha, Benjamin Johnston, Ishita Mathur
Book Image

The Supervised Learning Workshop - Second Edition

By: Blaine Bateman, Ashish Ranjan Jha, Benjamin Johnston, Ishita Mathur

Overview of this book

Would you like to understand how and why machine learning techniques and data analytics are spearheading enterprises globally? From analyzing bioinformatics to predicting climate change, machine learning plays an increasingly pivotal role in our society. Although the real-world applications may seem complex, this book simplifies supervised learning for beginners with a step-by-step interactive approach. Working with real-time datasets, you’ll learn how supervised learning, when used with Python, can produce efficient predictive models. Starting with the fundamentals of supervised learning, you’ll quickly move to understand how to automate manual tasks and the process of assessing date using Jupyter and Python libraries like pandas. Next, you’ll use data exploration and visualization techniques to develop powerful supervised learning models, before understanding how to distinguish variables and represent their relationships using scatter plots, heatmaps, and box plots. After using regression and classification models on real-time datasets to predict future outcomes, you’ll grasp advanced ensemble techniques such as boosting and random forests. Finally, you’ll learn the importance of model evaluation in supervised learning and study metrics to evaluate regression and classification tasks. By the end of this book, you’ll have the skills you need to work on your real-life supervised learning Python projects.
Table of Contents (9 chapters)

Splitting a Dataset

A common mistake made when determining how well a model is performing is to calculate the prediction error on the data that the model was trained on and conclude that a model performs really well on the basis of a high prediction accuracy on the training dataset.

This means that we are trying to test the model on data that the model has already seen, that is, the model has already learned the behavior of the training data because it was exposed to it—if asked to predict the behavior of the training data again, it would undoubtedly perform well. And the better the performance on the training data, the higher the chances that the model knows the data too well, so much so that it has even learned the noise and behavior of outliers in the data.

Now, high training accuracy results in a model having high variance, as we saw in the previous chapter. In order to get an unbiased estimate of the model's performance, we need to find its prediction accuracy...