Advanced – AI & ML Testing
NDCG – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
Normalized Discounted Cumulative Gain — a ranking quality metric that rewards putting more-relevant results higher.
In simple words
A metric for how well a ranked list puts the best results at the top.
Exam tip
NDCG is the dominant search-relevance metric — used in web, product, and RAG systems.
Related terms
Practice this term in the ISTQB Mock Test
40 CTFL v4.0 questions, 60-minute timer, instant scoring and chapter-wise breakdown.
Practice in Mock Test