Project Summary Sexual well-being (SW), the cognitive and emotional evaluation of an individual's sexuality, is an important aspect of overall health and quality of life, yet it is often overlooked in research and clinical practice. Issues around sexuality may have wide-ranging repercussions, from mental health problems to damaged interpersonal relationships, psychological distress, risky behaviors, to violence. Despite this, we still know little about which factors determine SW, and how to measure it. Existing self-report scales are either designed to be brief, only suitable for certain groups, and/or focus mostly on sexual functioning and the absence of negative factors such as coercion or sexually-transmitted infections. While this is important, it is not sufficient for optimal sexual health, which is “a state of physical, emotional, mental and social well-being related to sexuality;[...]not merely the absence of disease, dysfunction or infirmity” (WHO, 2006). Optimal SW may also encompass positive factors, such as feeling loved by one's partner, the ability to enjoy pleasurable experiences, and self- acceptance. Challenges in measuring SW hinders the research process, making informed decisions on sexuality education, and the development of impactful interventions. Here we address these gaps by developing a comprehensive model and in-depth scale of SW which includes positive, strength-based aspects of sexuality. Our team includes experts in sexuality, public health, psychology, and measurement scale development. We will use a proven, highly rigorous three-phase methodology over a five year project timeline. In phase one, we will identify all potential dimensions of SW by applying surveys, analyzing focus groups, conducting interviews, literature review, and more. Phase two focuses on validation of the identified dimensions and development of a robust SW measurement scale. We will first generate a pool of questionnaire items that cover all candidate dimensions and then use interviews, expert feedback, and pilot studies to refine them. Subsequently, we will conduct large-scale studies with thousands of participants to establish the scale's dimensionality using factor analysis, and will test scale validity across different subgroups of our samples. In the final phase, we will assess the value of the resulting SW scale for research and public health by administering it to 3000 participants in a U.S. nationally representative probability sample. We will examine how SW dimensions vary with age, gender, and other demographic variables, as well as associations with health and well-being. Participants will also rate the importance of each dimension, as individuals differ vastly in what they care about in sexuality. We will test whether incorporating importance ratings into scale item weights improve its ability to predict health outcomes. Ultimately, our research will deliver a robust SW scale with demonstrable value for predicting health outcomes, the...