The evolution of human-robot interaction (HRI) demands robust evaluative methods that capture not only technical performance but also the intricate social dimensions of robotic systems. This workshop examines the application of the ROSaS questionnaire as a systematic instrument for assessing social aspects and uncanny valley perceptions across diverse user profiles in different stages of the design. Drawing on empirical studies, the session explains how the ROSaS tool elucidates users’ perceptions of robot sociability and human-likeness, and how these perceptions enrich the understanding of formative affinity in the design of social robots. By providing participants with practical experience on prototyping social robots, this workshop aims to elucidate the determinants of robot warmth. Through scholarly presentations and in-depth discussions, participants will engage in a collaborative analysis of current methodologies and challenges, with the ultimate objective of refining evaluation practices that guide the design of human-robot interfaces in social robots. This workshop welcomes participants of all expertise levels.