What makes a successful machine learning model?
Until now, we have taken a largely quantitative perspective of what it means to be a successful machine learning model. Supervised learners were initially said to perform well if the accuracy was high.
In Chapter 10, Evaluating Model Performance, we expanded this definition to include other, more sophisticated performance measures, such as the Matthews correlation coefficient and the area under the ROC curve, to account for the fact that accuracy is misleading for unbalanced datasets and to consider performance trade-offs for potential use cases.
So far, we have relegated qualitative measures of model performance to the realm of unsupervised learning, although there are certainly non-quantifiable considerations in the area of predictive modeling as well. Consider, for example, a credit scoring model that is so computationally expensive that it cannot be implemented in a real-time application, or so algorithmically complex that...