Learn how representative samples and random samples differ and why combining them minimizes sampling bias for accurate data.

We collaborate with the world's leading lawyers to deliver news tailored for you. Sign Up for any (or all) of our 25+ Newsletters. Some states have laws and ethical rules regarding solicitation and ...

In sample surveys estimates are often required for subclasses of the population. The usual results assume that the domain numbers, M i, are either known exactly or completely unknown. The case where ...

Several states with extensive water use databases rely upon the census approach. That is, data are collected for all water users withdrawing amounts greater than a specified threshold that varies from ...

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 ...

The PROC SURVEYMEANS statement invokes the procedure. In this statement, you identify the data set to be analyzed and specify sample design information. The DATA= option names the input data set to be ...

Objective: To study the predictive power of serum selenium with regard to cancer mortality in a large sample of the Belgian population given the lack of coherence in the results of observational ...