Metrics, NLP, Search, Recommendation System, Evaluation.
and cannot determine how well answers are ranked. Discounted Cumulative Gain (DCG): summation of relevance(i) / log (i+1) Note: Log in base 2 DCG = (0 / log(1+1)) + (3 / log(2+1)) + (2 / log(3+1)) = 0 + 1.89 + 1 = 2.89 However, DCG is hard to interpret. Normalized Discounted Cumulative Gain (NDCG):