Brianna Sylver's article on Core77 is Spend it Wisely: A Market Research Primer for Designers. It comparatively summarizes key user research methods (e.g. ethnography, focus groups, surveys, etc) in terms of application, cost and time:
"sufficient time for analysis needs to be given to ethnographic-based initiatives. Fieldwork is a bit messy, as the protocols for ethnographic research are largely non-directed and unscripted. So it's only in the analysis of that data that you uncover the real nuggets of information that offer the AHA!"
Yes, very basic, but it's a primer after all.
