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

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Gordon Scott has been an active investor and technical analyst or 20+ years. He ...

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 ...