Abstract—The evolution towards cross-organizational collaboration and interaction patterns has led to the emergence of scalable, Web services-based composition infrastructures. The success of service-oriented architecture (SOA) was mainly influenced by the standardization of composition languages such as BPEL. However, compositions require humans to be in the loop and ways to interface with people in a service-oriented manner. In this paper, we discuss Human-Provided Services (HPS) enabling the seamless integration of human capabilities in SOA. In complex and large-scale environments, processes might span interactions among partially unknown participants residing in different organizational units. To address the problem of trusted selection of participants, we introduce a mining approach for the automatic inference of trust relations. Unlike a securitybased view on trust, our approach relates to the emergence of trust across humans and services from a social perspective. Keywords-in...