Survey design took place over
three years and was informed by focus groups, cognitive interviews,
and pretesting. The final survey instrument was implemented
by Knowledge Networks (now GfK) on a random sample of
the Knowledge Networks web panel of U.S. households utilizing a
Dillman Tailored Design Method Approach (Dillman et al., 2009)
that included multiple contacts using mixed modes (e-mail and
telephone).4