Update README.md

README.md

@@ -32,7 +32,7 @@ This is a copy of the [MS^2](https://huggingface.co/datasets/allenai/mslr2022) d
 - __retriever__: BM25 via [PyTerrier](https://pyterrier.readthedocs.io/en/latest/) with default settings
 - __top-k strategy__: `"oracle"`, i.e. the number of documents retrieved, `k`, is set as the original number of input documents for each example
 
-Retrieval results on the `test` set:
+Retrieval results on the `validation` set:
 
 |ndcg | recall@100 | recall@1000 | Rprec |
 | ----------- | ----------- | ----------- | ----------- |