FTS Scoring is inconsistent among identical search term results

[sreeks]

hi @The_Cimmerian,

Can you confirm whether the second hit’s name field (which was the 48th item among the 100 hits when you searched for “YAMA AUTOMOTIVE”) was having an exact text like - “SLIMS AUTOMOTIVE” alone Or was it just a part of the name of that document, meaning was the name containing any other extra texts in it?

You may also enable the “Explain” option in search request to have a glance on how the scoring/rank was arrived for each of the hits.
https://docs.couchbase.com/server/6.5/fts/fts-response-object-schema.html#request
And then sharing the explain output helps in checking this further.

Meantime you may also explore how the scoring works in FTS here -

https://docs.couchbase.com/server/6.5/fts/fts-troubleshooting.html

Understanding FTS score value

Hi @mosabusan, This is bit tricky to answer briefly. But let me try, FTS’s internal text indexing library(bleve) uses a slightly tweaked version of standard tf-idf scoring. This improvisation is done to normalise the score by various relevant factors. The search scoring happens at the query time. There isn’t a real pre-defined maximum score. When bleve scores a document - it sort of sums a set of sub scores to reach a final TotalScore. Scores across different searches are not directly compa…

Cheers!