Random sampling is a random means of gathering data points from all groups. It eliminates bias within your data sets by using ...

where is the true probability of observing the jth response level in the ith population. The product multinomial distribution is simply the product of two or more individual multinomial distributions ...

Suppose that the sample of students described in the previous section was actually selected using stratified random sampling. In stratified sampling, the study population is divided into ...

This paper presents the results of a limited investigation which brings into focus the difficulties encountered in developing exact distribution-free methods for stratified simple random sampling. It ...

Oct. 8, 2008— -- Surveys based on a random sample of respondents are subject to sampling error – a calculation of how closely the results reflect the attitudes ...

A new telephone survey experiment finds that, despite major structural differences, an opinion poll drawn from a commercial voter file can produce results similar to those from a sample based on ...