This paper compares the behaviour of sampling techniques for price indices by using a scanner data set as a model population. Indices produced by two purposive deterministic cut-off designs and four probabilistic sampling schemes are compared with each other and with the ‘true’ population index from the whole data set. We found that the two deterministic cut-off sampling schemes show much diffe...

We first review existing sequential methods for estimating a binomial proportion. Afterward, we propose a new family of group sequential sampling schemes for estimating a binomial proportion with prescribed margin of error and confidence level. In particular, we establish the uniform controllability of coverage probability and the asymptotic optimality for such a family of sampling schemes. Our...