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How to Calculate Precision, Recall, and F-Measure for Imbalanced Classification


Classification accuracy is the total number of correct predictions divided by the total number of predictions made for a dataset. As a performance measure, accuracy is inappropriate for imbalanced classification problems. The main reason is that the overwhelming number of examples from the majority class (or classes) will overwhelm the number of examples in the minority class, meaning that even unskillful models can achieve accuracy scores of 90 percent, or 99 percent, depending on how severe the class imbalance happens to be. An alternative to using classification accuracy is to use precision and recall metrics. In this tutorial, you will discover how to calculate and develop an intuition for precision and recall for imbalanced classification.

20 Popular Machine Learning Metrics. Part 1: Classification & Regression Evaluation Metrics


Choosing the right metric is crucial while evaluating machine learning (ML) models. Various metrics are proposed to evaluate ML models in different applications, and I thought it may be helpful to provide a summary of popular metrics in a here, for better understanding of each metric and the applications they can be used for. In some applications looking at a single metric may not give you the whole picture of the problem you are solving, and you may want to use a subset of the metrics discussed in this post to have a concrete evaluation of your models. Here, I provide a summary of 20 metrics used for evaluating machine learning models. There is no need to mention that there are various other metrics used in some applications (FDR, FOR, hit@k, etc.), which I am skipping here.

Model Evaluation Metrics in Machine Learning - KDnuggets


Predictive models have become a trusted advisor to many businesses and for a good reason. These models can "foresee the future", and there are many different methods available, meaning any industry can find one that fits their particular challenges. When we talk about predictive models, we are talking either about a regression model (continuous output) or a classification model (nominal or binary output). While data preparation and training a machine learning model is a key step in the machine learning pipeline, it's equally important to measure the performance of this trained model. How well the model generalizes on the unseen data is what defines adaptive vs non-adaptive machine learning models.

What is a Confusion Matrix?


The confusion matrix is capable of giving the researchers detailed information about how a machine learning classifier has performed with respect to the target classes in the dataset. A confusion matrix will demonstrate display examples that have been properly classified against misclassified examples. Let's take a deeper look at how a confusion matrix is structured and how it can be interpreted. What Is A Confusion Matrix? Let's start by giving a simple definition of a confusion matrix.