Aggregated search interfaces provide users with an overview of results from various sources. Two general types of display exist: tabbed, with access to each source in a separate tab, and blended, which combines multiple sources into a single result page. Multi-session search tasks, e.g., a research project, consist of multiple stages, each with its own sub-tasks. Several factors involved in multi-session search tasks have been found to influence user search behavior. We investigate whether user preference for source presentation changes during a multi-session search task.