Respondents’ interpretations of impact measures for dose-response studies

Abstract

Dose-response studies conducted at several National Park Service areas showed that respondents reported higher levels of impact for interference with the appreciation of natural quiet and sounds of nature than for the traditional annoyance measure of were you bothered or annoyed by aircraft noise during your visit to [SITE]? These differences led to questions about respondents’ interpretation of the two measures and the appropriateness of each for policy decisions. To probe this issue, 21 cognitive interviews were conducted with respondents to a dose-response survey sponsored by the USAF at White Sands National Monument. The interviews probed respondents’ question understanding and their interpretation of key phrases (e.g., bothered or annoyed and interference with appreciation of the sights and sounds of nature). In addition, they were asked how they selected scale points for each response and what types of events or conditions would prompt them to change their selected point. These qualitative data indicated that interference and annoyance were related concepts, but measured different types of impacts. Interference was interpreted as more event-specific and transitory, whereas annoyance was a summary evaluative term indicating a threshold level of negative reactions.