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initial documentation

README.md

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 license: apache-2.0
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+- Passage Re-Ranker a encoder based model that takes a search query, and a passage, and calculates the relevancy of the passage to the query. This is used in conjunction with sentence transformers to re-rank the passages matched by the sentence transformer, there-by improving relevance of Information Retrieval processes.
+- The Model is Finetuned using MS-Marco, and tested using Science QA datasets.
+- The Model is currently an integral part of `Neural Search` Information Retreival process used by the Science Discovery Engine, Along with the finetuned sentence transformer (https://huggingface.co/nasa-impact/nasa-smd-ibm-st-v2).
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+![image/png](https://cdn-uploads.huggingface.co/production/uploads/61099e5d86580d4580767226/jJnEkMijBvnTSN_cb_lDn.png)
+Fig. Passage Reranker Evaluation