This document discusses how to increase depth and complexity in the classroom to engage students and improve learning. It introduces prompts and icons that represent different thinking strategies to help students examine topics at deeper levels. Some of the prompts discussed for depth include details, patterns, rules, and unanswered questions. Prompts for complexity include different points of view, relationships over time, and relationships across disciplines. The document emphasizes using the prompts and icons within lessons, labeling work with them, and mixing them together to promote higher-level thinking. It provides keys to activate deeper and more complex learning using the language of different disciplines and considering different perspectives.