Estimation of percentage of children immunized in community as per WHO is to be done by:: (A) Multistage random sampling, (B) Cluster random, (C) Systematic random sampling, (D) All of the above
Answer is B. WHO recommends cluster random sampling (CRS) to estimate the percentage of children immunized in the community, paicularly in developing nations. Their recommended strategy is 30x7 sampling. Ref: Medical biostatistics, 1st edition pg: 201