Week 14 interactive
Model Evaluation Lab
Move a probability threshold and watch the confusion matrix, precision, recall, and accuracy change together.
Confusion matrix
4
actual positive / predicted positive
actual positive / predicted positive
2
actual positive / predicted negative
actual positive / predicted negative
3
actual negative / predicted positive
actual negative / predicted positive
3
actual negative / predicted negative
actual negative / predicted negative
Accuracy58%
Precision57%
Recall67%
Threshold0.50
Move the threshold until accuracy looks good, then check what happened to false negatives. A metric is useful only in the context of the error that matters.