ResearchBenchmarksRetrieval on NTCIR-15 Keyword (test)Retrieval on NTCIR-15 Keyword (test)Follow48.3MAPPIPER7.32417.96228.639.238May 18, 2026Evaluation resultsMethodMethodLinksMAPP@10R@10nDCG@10PIPERquery optimization=truequery optimization=true2026.0548.34356.357.8Dense-BGE2026.0534.2364848.7ColBERTv22026.0526.32736.939.8SPLADE2026.0525.32733.937.9BM252026.0520.42630.133PIPERquery optimization=falsequery optimization=false2026.0520152232.7TAPAS-base2026.058.91616.117.7