1 Wen-Ying Sylvia Chou is with the Health Communication and Informatics Research Branch, Behavioral Research Program, National Cancer Institute, Rockville, MD. Anna Gaysynsky is with the Behavioral Research Program, National Cancer Institute and ICF Next, Rockville, MD. Joseph N. Cappella is with the Annenberg School for Communication, University of Pennsylvania, Philadelphia. Wen-Ying Sylvia Chou and Anna Gaysynsky are also guest editors for this supplement issue.