Chapwanya, N. and Gorejena, K. 2025. Hybrid Unsupervised Machine Learning for Insurance Fraud Detection: PCA-XGBoost-LOF and Isolation Forest. Journal of Information Systems and Informatics. 7, 1 (Mar. 2025), 941-959. DOI:https://doi.org/10.51519/journalisi.v7i1.958.