Science policymakers are devoting increasing attention to enhancing the social valorization of scientific knowledge. Since 2010, several international evaluation initiatives have been implemented to assess knowledge transfer and exchange practices and the societal impacts of research. Analysis of these initiatives would allow investigation of the different knowledge transfer and exchange channels and their effects on society and how their effects could be evaluated and boosted. The present study analyses the "transfer sexenio" programme, which is a first (pilot) assessment that was conducted in Spain to evaluate the engagement of individual researchers in knowledge transfer to and knowledge exchange with non-academic stakeholders, including professionals and society at large. The breadth of the information and supporting documentation available (more than 16,000 applications and 81,000 contributions) allows an exploration of knowledge valorization practices in terms of the transfer forms used and the researchers involved--distinguishing between the Science, Technology, Engineering and Mathematics (STEM) and Social Sciences, Humanities and Arts (SSHA) areas. By focusing on SSHA fields, we explore knowledge dissemination via enlightenment or professional outputs. We conduct quantitative and qualitative analysis which provide a more comprehensive overview of knowledge transfer practices in Spain in the SSHA field, in particular, and has implications for future assessment exercises.