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

Many techniques in survey sampling depend on the possession of information about an auxiliary variable x, or a vector of auxiliary variables, available for the entire population. Regression estimates ...

The problem of estimating the variance of the ratio estimator in sampling with probability proportional to aggregate size is investigated. The form of nonnegative unbiased variance estimators is found ...

While previous sections of this report have focused on the kinds of systematic biases that may be the largest worry when it comes to public opinion polls, the variance (or precision) of estimates is ...

In a simple random sample, each individual in the population has an equal probability of being chosen. Additionally, each sample of size n has an equal probability of being the chosen sample. This ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...