An experience a week or so ago will nicely illustrate that. I was searching for PHP CMSes that have a tutorial to write modules, so I was searching for "php cms module tutorial" (without the quotes). I got to the search page and started furiously middle-clicking promising results. Once at the end of the page, there was a small note without any specific typesetting saying "Note: The word 'module' was dropped from your search results. Click here to search again with the word included." (Quoted from memory, so I may be a little off.)
Don't do that. If I ask for something, don't give me something else! And definitely don't do it without telling me beforehand.
They're doing something similar where they include a few results for something they think you ought to have searched for, then a horizontal rule, and then the thing you actually searched for. At least there I know it's happening, but it's still not what I asked for.
By all means, give me a suggestion if you think I made a mistake. But give me what I asked for anyway. Without me jumping through hoops for you. It messes up my train of thought :-(