In the comprehensive essays, you are expected to demonstrate the ability to integrate work done in the various knowledge area assessments.  This is a different task from what is expected for the knowledge area assessments, which focus on a specific body of theories and research.  

For the comprehensive essays, you will need to address a wide range of the relevant academic literature so that you can demonstrate knowledge across a set of the knowledge areas.  Think of the comprehensive assessment as an opportunity to display a synthesis and critical analysis of knowledge and skills you have acquired from your work in the knowledge areas.