Boolean Search Tool, K-12

http://www.boolify.org/index.php
Boolify makes it easier for students to understand their Web search by illustrating the logic of their search, and by showing them how each change to their search instantly changes their results. Boolify enables students to be able to visualize the search process by using puzzle pieces to put their search together. It uses the Google Safe Search engine so results are appropriate for children and it teaches children to use proper Boolean searches. While aimed at primary and middle-school children, Boolify is a great tool for anyone who is not familiar with the ins and outs of Boolean searching.