Pew Research Center’s cross-national studies are fielded in a range of polling environments, from countries where telephone surveys are regularly administered to nations where face-to-face surveys are ...

The value of strong questionnaire design, complemented by the task of high-quality sample development, is not fully appreciated. Too often researchers relegate those two essential building blocks of ...

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 French quality of life questionnaire specific to erectile dysfunction (ED), ‘QVS’ for ‘Questionnaire de Vie Sexuelle’, has been developed. This paper describes its validation: item reduction and ...