What is the best way to structure an ethnographic study? I'm writing an ethnographic study for a human computer interaction module and I understand all the processes of conducting ethnography. 

I am unsure of how to structure my study. Is it conventional to have it in an essay format, or are case studies preferred?
I have used ethnography for similar purposes several times. Structuring the interviews so that you are an apprentice and your subject plays the role of a master artisan works well.

The book, "Contextual Design" by Beyer and Holtzblatt provides several modeling techniques for expressing the information in some ways that add significantly to essay.

http://www.amazon.com/Contextual-Design-Customer-Centered-Technologies-ebook/dp/B003VM7GEC/ref=sr_1_1?ie=UTF8&amp;qid=1382970418&amp;sr=8-1&amp;keywords=holtzblatt