PROJECT SUMMARY/ ABSTRACT Despite significant efforts to limit youth from accessing and using electronic cigarettes (e-cigarettes), many adolescents and young adults are directly purchasing e-cigarettes from brick-and mortar retail stores. Studies show that pervasive e-cigarette marketing in the retail environment such as e-cigarette product displays, location/size of advertising, and price incentives and coupons, increase adolescent e-cigarette susceptibility and actual use. However, studies have not directly asked adolescents and young adults to identify appealing and influential characteristics of e-cigarette marketing in the retail environment that impact their e-cigarette purchase and use intentions. Such data will support the FDA’s aim of understanding marketing influences on youth tobacco use and will inform the development of communications to prevent e-cigarette use through a counter-marketing lesson, addressing appealing e-cigarette marketing characteristics in the retail environment. The proposed project will address three Specific Aims towards the development of a counter-marketing lesson and regulatory solutions: (1) Examine adolescents’ and young adults’ descriptions of e-cigarette marketing in the retail environment and its influence on their e-cigarette purchase and use behavior. (2) Identify the most important, appealing characteristics intrinsic to e-cigarette marketing in the retail environment influencing adolescents’ and young adults’ intentions to purchase and use e-cigarettes. (3) AIM 3. Develop and evaluate the effectiveness of an e-cigarette counter-marketing lesson combating marketing in the retail environment to reduce intent to use and actual use of e-cigarettes among adolescents. In the K99 phase, focus group discussions (Aim 1) and surveys including an embedded discrete-choice experiment (Aim 2) will identify how and which e-cigarette marketing characteristics influence adolescent and young adult e-cigarette purchase and use. Aims 1 and 2 will identify which characteristics require counter-marketing and would benefit from strengthened regulation. In the R00 phase, a randomized controlled trial will randomly assign adolescents-only to one of two conditions: 1) an online counter-marketing lesson about e-cigarette marketing in the retail environment (developed in this phase) or 2) an existing online e-cigarette overview lesson to assess influence on adolescents' intent to use and actual use of e-cigarettes (Aim 3). This Award and proposed research will enable the PI to grow expertise in impactful e-cigarette prevention programs and policy solutions to reduce adolescent tobacco use, a long-term goal. A training plan involving mentorship from multidisciplinary tobacco control experts in tobacco prevention, marketing, policy, survey design, statistical methods and counter- marketing design, and complementary didactic training will fill gaps in knowledge of tobacco regulatory science and vital research skills, allowing the ...