By Catherine Gewertz
Take a look at ELA Standard 10: "Read and comprehend complex literary and informational texts independently and proficiently."
Appendix A of the standards... outlines the standards' approach to figuring out a text's complexity.
A supplement to Appendix A (http://corestandards.org/assets/E0813_Appendix_A_New_Research_on_Text_Complexity.pdf), issued today, expands on the original Appendix's approach to text complexity, based on a new study done to inform this process.
Via Mel Riddile