It will become the standard survey for some years to come.
Obviously, that's a bigger margin than other polls are showing: in fact, it's the first survey for some time to show Obama with a lead larger than the statistical margin of error.
For each couple registering for marriage, both individuals were invited to participate in the survey; for some couples both individuals participated; for others, only one person.
Age was reported by participants as part of the survey; for some participants with missing self-reported age (n = 19), we used birth dates from administrative records that were collected as part of the ChE monitoring program.
If it was taken at a time when Mr. Santorum was doing especially well in national surveys, for instance, then some of his performance will reflect the national trend rather than anything intrinsic to the state.
It should be noted that despite efforts to standardize, the definition of certain categories of health occupations may have varied across surveys; for example, in some cases the classification of nurses and midwives did not distinguish between professionals and associate professionals.
Those who took part in behavioral studies typically considered the research tasks and participation to be relatively innocuous or non-intrusive (e.g., surveys, interviews); for some they were an opportunity to satisfy an interest or share their experience.
David Binder, a pollster who has conducted some surveys for supporters of Mr. Newsom, said the wild card in the race was the large number of young Gonzalez volunteers.
Finally, in the 2007 survey and for some respondents in the 2012 survey, although the cost per visit or purchase was collected as continuous data within the range of $0-$0-$500r expendithee, the number of visits or purchases per person was collected as categorical data (based on recommendations from cognitive testing).
