This case study focuses on a multidecade time-series study of changes in public acceptance of evolution in the United States. Change over time is often a central issue in social science research. There are two kinds of change over time. Time-series studies address change in populations or groups over time. Longitudinal studies address changes in individuals over time (see related longitudinal case study in this collection). This case study will describe the process for conceptualizing a multiyear time series and the challenges of obtaining funding for multiyear studies. This case study is based on a series of US probability samples and will discuss the importance of probability-based samples and some of the problems of building probability samples over the years since World War II. The case study will also discuss the impact of changing data collection technologies on time-series studies. Readers will be challenged to think about the impact of potential changes in survey research sample selection and survey administration in the decades ahead. [This content is provided in the format of an e-book.]