"If you want to be able to read with comprehension, you must become knowledgeable about the topic. The more relevant knowledge you have, the less it matters whether the text is complex or not," write Hirsch and Hansel in this article. Research has shown that a student who has extensive background knowledge of a topic will find it easy to comprehend a text on that topic, no matter how complex the writing. On the other hand, even a skillful reader will have trouble comprehending a text on a topic that he or she knows nothing about. The Common Core State Standards in Language Arts and Literacy have acknowledged the importance of content knowledge to reading comprehension by recommending that schools implement a carefully sequenced, domain-based curriculum that expands and deepens students' knowledge as they progress through school. The authors describe how the K-3 curriculum developed by the Core Knowledge Foundation (available for free download) can help schools achieve this goal and transition to the new Common Core standards.