PROJECT SUMMARY Adults who are socioeconomically disadvantaged (“Low-SES”) are at increased risk of heavy smoking, face reduced cessation success, and bear a disproportionate burden of smoking-attributable morbidity and mortality. Encouraging smokers who are not able or ready to quit smoking to switch to lower harm non- combustible products could reduce this burden. However, the success of these efforts relies upon smokers understanding that the health risks of nicotine-containing products are not identical but lie along a continuum, with combustible products being the most harmful and noncombustible products being significantly less harmful. Studies have identified a general lack of knowledge about the relative risks of nicotine-containing products across the population, and evidence suggests that low-SES adults may be less knowledgeable than higher-SES adults about the continuum of risk (COR). There is still a lack of evidence about COR perceptions among low-SES smokers, the effectiveness of educational messages designed to boost COR knowledge, and whether increasing COR knowledge increases intentions to switch products and reduces combustible product use. This proposal aims to 1) use qualitative methods to assess COR perceptions among low-SES smokers, 2) design and test candidate COR educational messages, and 3) investigate the effects of exposure to COR educational messages on COR knowledge, intentions to switch from combustible to noncombustible products, and reductions in combustible product use among low-SES smokers. A comprehensive training plan will ensure successful execution of these aims, with four overall goals for the PI during the training period: 1) proficiency in qualitative research methodology, 2) acquire expertise in clinical trial administration, leadership, and methodology, 3) acquire expertise in advanced statistical methods to evaluate the effects of interventions, and 4) develop expertise in designing, optimizing, and testing health communications. Training will be guided by a team of expert mentors with complementary areas of expertise and current, strong collaborative relationships with one another. The research and associated training will also be supported by the strong training environment at Virginia Commonwealth University. This K01 will prepare the PI to successfully lead future independent studies focused on reducing the burden of tobacco and other substance use among vulnerable populations.