Metrics to measure machine learning model performance

Prediction is an iteration task: you build your model, measure its performance and start again until you make progress. And progress is measured by metrics. Thus, metrics are the only way to understand if you are doing a good job or not. The choice of which metric to use depends on various factors, including the problem you are trying to solve; how you want to penalize errors and the model you are building. Let's discuss some of these metrics by clustering them by predictive model type.