Glossary

Attrition risk – probability a person will leave.
Effectiveness – chance an intervention prevents an otherwise likely leaver.
Replacement cost – money lost when someone leaves (recruitment, onboarding, productivity).
Top-K – the highest-risk K% of employees.
Coverage – % of the targeted cohort you can treat.
Threshold-free savings – probability-weighted expected value across the treated group.
TP – True Positives.
FP – False Positives.
TN – True Negatives.
FN – False Negatives.
Precision – TP / (TP + FP) i.e., how often the model correctly identifies a leaver.
Recall – TP / (TP + FN) i.e., the proportion of all leavers correctly identified.