For his research study on the housing eviction crisis, sociologist Matthew Desmond "moved into a rooming house and a trailer park to document the lives of the tenants struggling to pay rent." (Fresh Air podcast, April 12, 2018). Dr. Desmond's work most likely follows a(n) _________ research design.
1) Cross-sectional
2) Cohort
3) Experimental
4) Quasi-experimental
5) Ethnographic