ABSTRACT
This chapter discusses approaches to use, analyze, and interpret observations from the site where the effect has been observed and nearby comparison site(s) where the effect has not been observed or has been observed in a different way. It begins by discussing sensory evidence from the case, such as might be documented during site visits. Although qualitative in nature, this evidence can be just as useful and compelling as that derived using quantitative methods. The chapter describes the types of analyses that can be applied to quantitative measurements potentially available at the early stages of an assessment. The results obtained from analyzing case-specific observations are typically the first to be scrutinized. As additional evidence is accumulated, the interpretation will likely evolve. Associations from case-specific observations are most informative when analyses are conducted for many candidate causes, interpreted in the context of conceptual models, and used with additional sources of information and approaches for developing evidence.
