6.2 Vector Space Retrieval 133
Word Number of occurrences Number of documents
the 61735764 7656676
of 56188095 8838209
and 35936471 7398465
in 33774127 7492125
to 18670139 5482347
a 18257728 5846177
with 12881242 4904841
was 10202515 3683332
for 8961803 4155330
human 8823139 7284714
were 8569580 3348418
by 8312546 3872850
that 7060247 3500824
is 6941721 3340361
metabolism 6459988 2119436
on 5669049 3324379
effects 5383334 2450007
from 5230712 2868785
drug 5141572 2305403
patients 5120897 1680125
as 4631373 2635318
or 4628590 2551277
at 4127714 2236276
cells 4112303 1303540
blood 4040580 1646084
this 3982055 2657101
an 3942049 2647511
male 3908310 3580224
be 3803795 2491683
female 3777242 3496974
support 3751655 2924479
pharmacology 3667686 1550452
analysis 3660441 1964018
are 3650898 2205386
Table 6.1 Number of occurrences of the most common words in PubMed