From 28 May 2012 to 30 June 2012, the Afrobarometer surveyed a nationally representative, random, stratified probability sample of 2,400 adult Tanzanians. Face-to-face interviews were conducted in the language of the respondent’s choice by the Afrobarometer team based at Research on Poverty Alleviation (REPOA). Local language translations were done in one language: Kiswahili. IDS provided technical backstopping for the survey. Previous Afrobarometer surveys were conducted in Tanzania in 2001, 2003, 2005, and 2008.
The sample was drawn by taking the smallest geographic units, Census Enumeration Areas (EAs), and stratifying all EAs across the country into separate lists according to regions and geographical area (urban/rural). 300 EAs were then randomly selected from these lists with the probability proportionate to its size in the overall population as represented in 2012 population projections provided by Tanzania’s National Bureau of Statistics based on the 2002 National Population and Housing Census. This ensured that every eligible adult had an equal and known chance of being selected. Eight households were then randomly selected within each EA, and a respondent 18 years of age or older was randomly selected from each household. A gender quota ensured that every other interview must be with a female. A sample of this size is sufficient to yield an overall margin of error of +/-2 percent at a confidence level of 95 percent.