What statistics/metrics are used to evaluate RAG systems? Is there any paper that systematically compares different RAG methods (chunkings, models, ect)? I woul

What statistics/metrics are used to evaluate RAG systems? Is there any paper that systematically compares different RAG methods (chunkings, models, ect)? I would assume that such metric would be similar to something used for evaluating summarization or question and answering but I am curious to know if there are specific methods/metrics used to evaluate RAG systems.