What a search does to the shortlist

Each search is retrieved exactly as the question is: by words, by meaning, and the two fused. Chapter 5’s retrieve already takes the searches argument, and for each one it adds two more rankings to the fusion. A question with two searches is six rankings fused into one list.

The pool is the list retrieval hands to the next stage, and its size is the second measurement in this chapter. Fusing a search’s two rankings beside the question’s own moves laws out of the pool as well as in: a law that is mediocre in every ranking outscores one that is first in the question’s ranking alone, because reciprocal rank fusion rewards consistency. By words alone, Pennsylvania’s move-over law was within the first 24 for its question and out of them once two searches were fused, and so were Nevada’s, New York’s, Ohio’s and Texas’s implied-consent laws, all within 32, and California’s implied-consent and pass-on-right laws were out at 32 too. The deployed pipeline widens the pool from 24 to 32 whenever searches were fused, and the count is from the pull request that introduced the rephraser. Chapter 7 reads that pool.