You get a plot showing exactly where underfitting turns into overfitting. You don't guess the max_depth anymore. You see the elbow. Most developers use visualizer.show() . Power users use visualizer.finalize() .
Enter . It’s not another visualization library. It’s a diagnostic suite that turns your Jupyter notebook into a model operating theater. The Core Insight: Visualizing Failure Modes Most ML tools tell you how well you did (accuracy, F1 score). Yellowbrick tells you why you did poorly. It extends Scikit-learn’s API to create visual "stress tests" for your models. yellowbrick development tool
# This isn't just plotting. This is validation. from yellowbrick.model_selection import ValidationCurve from sklearn.ensemble import RandomForestClassifier visualizer = ValidationCurve( RandomForestClassifier(), param_name="max_depth", param_range=range(1, 11), cv=5, scoring="f1_weighted" ) visualizer.fit(X, y) visualizer.show() You get a plot showing exactly where underfitting