Google has been automatically dropping terms from searches that give few or no results for some time. It now looks as though Bing may be doing the same. Unfortunately I cannot give the details of the search that brought this to light as it was confidential research. In general, though, what we were searching for were announcements or news articles about two companies involved in a particular project. We hadn’t found anything in Google so we tried various alternative search engines including Bing (http://www.bing.com/). The results seemed quite promising until we started looking at the individual pages. None of them had all of our terms. It is possible that the missing terms appeared in links to the pages but the content of the documents suggested that this was unlikely, and there is no reliable free tool that shows you who is linking to a specific page. So it looks as though Bing is now dropping terms in the same way that Google does.
There are two ways to stop Bing doing this. The first is to use the Boolean AND operator between all of your terms. The second is to prefix the term that must be present in a document with ‘inbody:’, for example inbody:aardvark.
Did we find anything that answered our question? No, but sometimes I don’t expect to and it is frustrating when the search engine thinks it knows best and unilaterally decides to rewrite the search strategy.
For a list of all of the Bing advanced search commands go to http://msdn.microsoft.com/en-us/library/ff795620.aspx