Metrics, NLP, Search, Recommendation System, Evaluation.
DCG / DCG(i) DCG(i) is DCG scored for an ideal answer. The ideal answer is the golden label provided by the annotator. Hence, in the above example, DCG(i) is the DCG score for Mjolnir, Stormbreaker, and Jarnbjorn. Let's first calculate the cumulative gain for the ideal answer. Relevance Score