The main types of non-response are no contact and refusal. In Chapter 2, we discuss some theories for these types of non-response. In addition, we present an overview of the characteristics associated ...

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 ...

A growing share of polling is conducted with online opt-in samples. 1 This trend has raised some concern within the industry because, while low participation rates pose a challenge for all surveys, ...