Additional Notes

Matrix Factorization

Crossvalidation

Metrics

• PSP[0,1]: cares about the item being in the list. Protected Feature/Item. PSP = -1 (all non-protected). PSP = 1 (all protected). PSP = 0 (It is equally divided 50/50).
• NDCG[-1,1]: (accumulative weight) cares about the order. The higher the NDCG, the more closely follows the test data.
• Expected Exposure: additional way of comparing the rating.