I saw the explanation of field-norm is: norm(d) = 1 / √numTerms, and in the "put it together" section in the following page:
it gave one example:
doc(and the only doc in the corpus) is "quick brown fox"
query is "fox"
however, the fieldNorm in this case is "0.5". As I understand it, the norm should be 1/√3, as 3 terms are there in the "quick brown fox".
Can someone tell me how this o.5 comes from?