Children encounter new words every day. Although dictionaries designed for young readers can help students explore and experiment with language, it turns out many mainstream children's dictionaries fail to accurately describe the world in which many students live. The challenges to children's dictionary publishers can be steep. First, there is the rule that definitions should only include terms that are also found in the same dictionary. Then there is the fact that children's reference materials aren't updated as frequently as adult volumes--often because sales numbers don't demand it. As a result, their content can sometimes lag behind the rapidly changing language in a high-tech culture.