Reranking Search Results
Reranking is the process by which an initial set of query results is rescored to produce a more refined and accurate ranking. It's usually performed with a machine learned model that, in contrast to the extremely fast retrieval step, is slower but more accurate.
Reranking is a beta feature in the platform, and only available as a single
reranker for English results, and can be enabled by specifying 272725717 as
the reranker_id
.
In order to use the reranker you need to specify two additional parameters in
the request: start
and numResults
. These tell Vectara
which results to rerank. In most scenarios, it makes sense to set start
to
0 so that you're reranking all of the best initial results, and then to set
numResults
to the total number of documents you wish to rerank.