Nature of the Sample: 938 U.S. Residents

This survey of 938 United States residents was conducted on August 3rd through August 6th, 2009. Residents 18 years of age and older were interviewed by telephone. Telephone numbers were selected based upon a list of telephone exchanges from throughout the nation.  The exchanges were selected to ensure that each region was represented in proportion to its population. To increase coverage, this land-line sample was supplemented by respondents reached through random dialing of cell phone numbers. The two samples were then combined. Results are statistically significant at 3.2%. The error margin increases for cross-tabulations.