Analysis of variance (ANOVA) is a statistical analysis tool that separates total variability found within a data set into two components: random and systematic factors.

Pew Research Center designed this study to assess the current state of online survey sampling methods – both probability-based and opt-in – and determine their accuracy on general population estimates ...

Probability-based panel: This refers to a national survey panel recruited using random sampling from a database that includes most people in the population. Today, most such panels in the United ...