FT.Search - scoring TFIDF (default)

Redis modules RediSearch
1

Trying to understand how below norm 3 is calculated by FT.Search with default scoring -> TFIDF.
Yes I have read the docs here: https://oss.redislabs.com/redisearch/Scoring/ but it is not 100% clear.

Thanks

1) "18.333333333333332"
    2) 1) Final TFIDF : words TFIDF 110.00 * document score 1.00 / norm 3 / slop 2
       2) 1) 1) (Weight 10.00 * total children TFIDF 11.00)
            2) 1) (TFIDF 6.00 = Weight 1.00 * TF 1 * IDF 6.00)
                2) 1) (Weight 1.00 * total children TFIDF 5.00)
                   2) 1) (TFIDF 5.00 = Weight 1.00 * TF 1 * IDF 5.00)
2

Hello bogumil,

The documentation states “normalized by the highest term frequency in each document”.

This means that after the TFIDF score is calculated, the score is divided by the maximum number of times any term appeared in the document. This will normalize the score between long and short documents and gives weight to the cardinality of terms.

TFIDF.DOCNORM is very similar but will instead divide the score by the total number of terms in the document.