Just what is meant by Text Complexity in the CCSS

Text Complexity is one of the keys in understanding whether or not your the text you are working with  is "rigorous" enough for your learners, for your grade level common assessment work, etc.  Certainly the level of thinking or Depth of Knowledge is also key. DOK Question Stems  

Depth of Knowledge - Level 3 Questions 
• How is ____ related to ____?
• What conclusions can you draw _____?
• How would you adapt____to create a
different____?
• How would you test____?
• Can you predict the outcome if____?
• What is the best answer? Why?
• What conclusion can be drawn from
these three texts?
• What is your interpretation of this text?
Support your rationale.
• How would you describe the sequence
of____?
• What facts would you select to
support____?
• Can you elaborate on the reason____?
• What would happen if___?
• Can you formulate a theory for___?
• How would you test___?
• Can you elaborate on the reason___?
Depth of Knowledge - Level 4 Questions 
• Write a thesis, drawing conclusions from
multiple sources.
• Design and conduct an experiment.
Gather information to develop
alternative explanations for the results of
an experiment.
• Write a research paper on a topic.
• Apply information from one text to
another text to develop a persuasive
argument.
• What information can you gather to
support your idea about___?
• DOK 4 would most likely be the writing o