You will either have read about this on other blogs or found out yourself when searching that Google has dumped the ‘+’ operator. This was a useful way to stop Google automatically searching for variations and synonyms of your terms. The theory was that by prefixing your term with a plus sign Google would be forced to look for an exact match. Try it now and Google tells you to use double quotation marks around the term instead. To be honest, the + sign has not worked reliably for several months but I often have the same problems with the double quotation marks. If I search on St. “Laurence” or “St. Laurence” Google still includes page on St Lawrence in my results.
Search Engine Land has covered the news and the reason why + has been dumped in “Google Removes The + Search Command” http://searchengineland.com/google-sunsets-search-operator-98189. It suggests + has been dumped because of Google+, their social network, and Google now suggests auto completing your friend’s names when you use the operator. As Danny Sullivan comments “it seems to have been tossed out and replaced by quotes because of a problem Google created for itself, by picking stupid names for its social network.”
I’ve noticed anther worrying trend – Google does not always look for all of my terms in the page. Viewing the cached copies of some of my results I see that not only are some of my terms missing from the page itself but they are not even in links to the page. So is Google now deciding when to ‘OR’ our search terms?