I realized this past year: Before teaching students how to use the Google advanced searching features (+, -, ~) it helps to talk in general about search strategies and keywords. Often, students don’t actually understand how search engines work. In fact, I’m sure there are lots of adults that don’t really know either. So taking a moment to explain how crawling/spidering and indexing work can really help students get it. You’re not supposed to type in a description of the information you’re looking for. You’re supposed to type in words that might appear on a web page that contains the information you’re looking for. A close, but important, distinction.