Discussion ●Possible reasons for differences between surveys : ● Different sampling designs : Sr = Simple random sampling Systrs = Systematic random sampling Stratrs = Stratified random sampling Ms = Multi-stage sampling Final sampling units: P = Persons H = Households A = Addresses T = Telephone numbers D = Dwellings But : Sampling design depends more on country than on survey  Survey design often constrained by what is available in the country
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