Average valence of respondents' general essay comments. The mean valence of respondent comments when asked their general reactions to the public health essay by audience segment and by a national population estimate. Note: 1 = (entirely positive comments); 0 = (mixed, including both positive and negative comments); and -1 = (entirely negative comments).
Maibach et al. BMC Public Health 2010 10:299 doi:10.1186/1471-2458-10-299