# Beyond-Accuracy: Coverage, Diversity (ILS), Novelty, Serendipity, and Popularity Bias Measurement

> Source: https://sukruyusufkaya.com/en/learn/oneri-sistemleri/beyond-accuracy-coverage-diversity-novelty-serendipity
> Updated: 2026-05-13T13:29:34.294Z
> Category: Öneri Sistemleri
> Module: Module 3: Evaluation Protocols
**TLDR:** Why does a recommender with high NDCG but bored users exist? Because only 'accuracy' was measured. Coverage, intra-list similarity (ILS), novelty, serendipity, gini coefficient measure all faces of the system.