The effect of personalization on mail survey response rates was examined in nine studies that included 17 comparisons under several research conditions. A study of this variable across multiple experiments in five agricultural experiment stations was undertaken because of conflicting results from previous research and from concern that the effectiveness of personalization might have decreased over time. Results show that, while response to general public surveys appeared to increase modestly across all treatment groups, there was no positive effect for populations in which a group identity (e.g., Dear Oregon Gardner or Dear ATV Owner) is employed to address respondents in cover letters. Personalization appears to remain useful for improving response in surveys of the general public. (Contains 2 tables.)