Considerations for retrieval metrics in RAG
In the context of RAG, we need to define relevance carefully. A document might be relevant to the query but not contain the specific information needed to answer it accurately. We might need to use a stricter definition of relevance, such as “contains the answer to the query.” As mentioned earlier, relevance in RAG is often context-sensitive. A document might be relevant to the query in isolation but not be the most helpful document for generating a specific answer given the other retrieved documents.
While metrics such as Recall@k and Precision@k focus on the top k retrieved documents, it’s also important to consider the overall quality of the retrieval across a wider range of results. Metrics such as Average Precision (AP) can provide a more holistic view.
Let’s illustrate how to calculate Recall@k, Precision@k, MRR, and NDCG@k in Python using the sklearn library:
- We first import the necessary libraries...