ResearchBenchmarksRetrieval on NTCIR-15 Complex NL (test)Retrieval on NTCIR-15 Complex NL (test)Follow56MAPPIPER1.415.57529.7543.925May 18, 2026Evaluation resultsMethodMethodLinksMAPP@10R@10nDCG@10PIPERquery optimization=truequery optimization=true2026.05564864.767.6Dense-BGE2026.0536.43646.851ColBERTv22026.0524.22838.938.9SPLADE2026.0523.42837.338.6BM252026.0519.22534.733.6PIPERquery optimization=falsequery optimization=false2026.0516.11518.823.3TAPAS-base2026.053.51110.412.8