This distribution depends on factors including the sample size ... and the procedure used to draw the sample sets determine the variability of a sampling distribution. The standard deviation ...

The prevalence of sampling errors can be reduced by increasing the sample size. In general ... systematic approach to selecting a sample. For example, rather than choosing participants to be ...

The nuts and bolts of our public opinion surveys. A summary of ABC News' polling standards and survey methodology follows. ABC News maintains standards for disclosure, validity, reliability and ...