... 3St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada, 4Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada, 5Harvard Humanitarian ... a list is unavail-able, but households are arranged in some geometric pat-tern and the investigators is aware of the number ofhouseholds, the investigator can choose one household ina cluster ... timethat the survey took place might differ from our own situ-ation. In order for findings to be useful, they should to besimilar to the current situation or provide strong historicalcontext that...