Frequency per million with a corpus, subcorpus and text type

The frequency per million is always related to the whole corpus or subcorpus, not to a text type. Restricting the query to one or more text types will affect the number of hits but the frequency per million will stay calculated using the number of tokens in the whole (sub)corpus.

To realte the frequency per million to one or more text types, create a subcorpus from the text type(s) and restrict the query to this subcorpus.

Example

Looking up the frequency of the word helps  in the British National Corpus (112,181,015 tokens), first in the spoken Text type and then in the spoken subcorpus will produce these results.

subcorpus selectednonenonespoken
11,787,138 tokens
text type selectednonespokennone
hits3,116302302
frequency per million27.75
in relation to the number of tokens in the whole corpus
2.69
in relation to the number of tokens in the whole corpus
25.62
in relation to the subcropus size
possible interpretationhelps appears 27.75 times per million words in BNC‘spoken’ helps appears 2.69 times per million in BNChelps appears 25.62 times per million in the spoken part of BNC