I was introduced to the Boolify project a few weeks ago when our teacher-librarian demonstrated it with my grade 4 class. Based on Boolean logic, the site uses Google's safe search STRICT technology, to help students better understand their searches and find the specific information they need.
Searches are visual and students can link together boolean puzzle pieces to help refine their searches. As they narrow down their search, the results are displayed below, giving students immediate feedback on their search results.
Boolify is a great tool to help students learn how to do better searches, in a way that is safe and fun.
Be sure to also check the other tools that the site has available for educators to use.