The random sample survey is a commonly used method in market research and such surveys generally are considered to provide more robust results than purposive or convenience (such as quota) samples.

Consider a population in which the variable of interest tends to be at or near zero for many of the population units but a subgroup exhibits values distinctly different from zero. Such a population ...

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 ...

Mary Hall is a editor for Investopedia's Advisor Insights, in addition to being the editor of several books and doctoral papers. Mary received her bachelor's in English from Kent State University with ...