Survey research is rapidly moving online – it’s cheaper, faster, provides greater flexibility in questionnaire design, and often has substantial advantages in data quality compared with phone surveys. …
Surveys that include only those who use the internet (and are willing to take surveys online) run the risk of producing biased results. And, in fact, a notable share of Americans either cannot or will not complete a survey via the internet.
That raises two questions: Whom do you miss with a Web-only survey, and how does it affect your results? CONT.
Eileen Patten & Andrew Perrin, Pew
