The purpose of the Confidentiality Notification Experiment was to determine the effect of confidentiality-related messages, written in language that respondents can easily understand, embedded in the cover letter that accompanied the initial census questionnaire mailing. The effect of two messages are of interest to this study: an administrative records-use message, which has not previously appeared in decennial production cover letters, and an alternative to the “standard” statistical purposes statement that was used in 2010 Census production materials. With regard to a administrative records data-linkage message, there is no definitive legal requirement that the U.S. Census Bureau provide respondents with a data-linkage notification; however, policy considerations come into play and stakeholders have recommended the inclusion of such a statement.