Creating a community-partnered measure of broad communication skills in autistic adults - Autistic adults universally face communication difficulties, yet no multi-dimensional measure of communication has been specifically validated in this population. The absence of such a measure is a barrier to advancing our understanding of communication strengths and challenges in autism – and how they may predict outcomes such as employment, health, and relationships. The objective of the current application is to develop and validate a comprehensive communication measure for autistic adults, using COSMIN standards for measure design. The project will use an iterative, mixed-methods, Community-Based Participatory Research (CBPR) approach, leveraging the PI’s existing team of autistic community partners as co-researchers in all study phases. The rationale for this approach is that research on marginalized populations should be conducted collaboratively with those affected, to ensure ethical, impactful, and scientifically sound processes and outcomes. The measure developed through this study, the C-SCAN (Communication Strengths, Challenges, and Nuances), will be grounded in both the established experimental literature on communication differences in autism, and the emerging literature on autistic adults’ internal experiences of communication. The C-SCAN will generate profiles of communication abilities and challenges, and will be designed for maximum accessibility to ensure valid data from the target population. Critically, the C-SCAN will be inclusive of the entire autism spectrum, accomplished by creating two versions: one for autistic adults to complete as a self-report measure (Aim 1), and one for proxy reporters (i.e., support people who will report on behalf of autistic adults who cannot complete the measure, even with support; Aim 2). Both instruments will be created through five rounds of a CBPR-Nested Delphi process involving (1) autistic adults or proxy reporters, as appropriate to the instrument version, (2) communication scientists, and (3) other professionals, such as clinicians, attorneys, employers, or direct support personnel. The research team, in collaboration with community partners, will draft instructions, response options, and item formatting based on best practices in accessible instrument design. For each instrument, we will test and refine content validity through an iterative series of cognitive interviews with a diverse sample of autistic adults and support people. Successful completion of the proposed project will result in two distinct versions of a multi-dimensional, community-driven measure of communication skills and experiences tailored for use by autistic adults. This contribution lays the groundwork for validating and disseminating a first-of-its-kind measure of a core feature of autism (communication differences) with robust links to outcomes, addressing community interests and needs. This innovative approach to instrument development in communication disorders research is expected to advance communication measurement, accelerating large-scale autism phenotyping research, outcomes research, and intervention planning.