Isolation Forest
Definition
An unsupervised machine-learning model for anomaly detection. It builds random decision trees and scores each record by the average depth required to isolate it. Anomalous records are isolated in fewer splits and receive high anomaly scores. No labelled fraud cases are required for training.
Related terms
- Anomaly scoring
- A numeric score assigned to each entity or transaction based on how different it is from the expected population, derived from multiple...
- Explainability
- The degree to which a model's output can be explained in terms of its inputs and logic. Logistic regression and decision trees...
- Logistic regression (supervised fraud model)
- A classification model trained on historically labelled transactions (fraud vs. legitimate) to estimate the probability that a new transaction is fraudulent. Requires...
- Network analysis (link analysis)
- A method that models entities (people, companies, accounts, addresses) as nodes and connections between them (shared attributes, transactions, ownership) as edges, then...
- Timeline reconstruction
- The assembly of events from multiple data sources onto a chronological axis to establish the sequence of actions in a fraud: when...
Explained in
- Data Analytics in Fraud InvestigationsAn unsupervised machine-learning model for anomaly detection. It builds random decision trees and scores each record by the average depth required to isolate i...