Monitoring Controversial Environmental/Natural Resource Issues: Differential Effects of Telephone and Mail Surveys

Monitoring public opinion, especially about controversial environmental/natural resource issues, through various survey modes remains an important social science tool used by scholars, advocates, newspaper reporters, and policymakers alike. However, with this use there has been a concomitant decline in response rates. To address this problem, increased use of mixed modes of surveys has occurred. The degree to which results of different modes can be combined remains a basic question. Can findings be compared to assess changes in public views across time or differences among various regions when different modes of data collection are used? We addressed this question by assessing how two comparable samples of residents' responses to the same questions differed depending upon survey mode (telephone or mail) while controlling for sampling procedures and survey content.