With the polysearch engine maintained by Peter Jacso, professor at the University of Hawaii, it is possible to do some evaluations to check whether the Google Scholar finds more or fewer hits than the native search engine of the publisher. The publishers you can compare is Annual reviews, Blackwell, Institute of Physics, Nature publ. group, Wiley Interscience. You can perform fulltext search or title search. I would suggest that you use title search because Google Scholar does not index the entire fulltext, just to a certain limit of KB. Which Anurag Acharya of Google Scholar told me in an interview made in September 2005 in Copenhagen.

As Jacso instructs don’t use the search operators beside of proximity search with ” “. I tried some searches which gave me the following results:

Annual Reviews (Native) 2 hits
Annual Reviews (Google Scholar) 6 hits

“frontotemporal dementia”
Blackwell (Native) 24 hits
Blackwell (Google Scholar) 18 hits
Check a screenshot from the search.

“fuzzy logic”
Institute of physics (Native) 8 hits
Institute of Physics (Google Scholar) 7 hits
Nature (Native) 45 hits
Nature (Google Scholar) 23 hits

“semantic web ”
Wiley interscience (Native) 8 hits
Wiley interscience (Google Scholar) 13 hits