The document discusses selecting complex texts for middle and high school ELA classrooms that are aligned to the Common Core standards. It provides examples of complex text types like legal opinions, editorials, and scholarly journals. It also discusses how to measure text complexity, including quantitative measures like readability tests and qualitative measures like text structure, language features, and required background knowledge. The document emphasizes that teachers should model close reading of complex texts, establish a clear purpose for reading, and scaffold support to help students comprehend challenging material and develop important reading skills.