Surveillance systems in Uganda detect that HIV prevalence declined from 21.1 percent in 1991 to 6.4 percent in 2001. The most common explanations for this decrease are that the population mobilized itself with the consequence that more people were faithful to their partners, or abstained from...

Sampling theory facilitates development of economical, effective and rapid measurement of a population. While national policy maker value survey results measuring indicators representative of a large area (a country, state or province), measurement in smaller areas produces information useful...