Understandability and completeness are essential in modern collaborative digital platforms and their learning systems. These platforms have shaken up the traditional education setting, particularly in leveraging the coauthoring approach in problem-solving and streamlining the learning behavior of cowriting or corevising. Such a learning context has attracted considerable interest from various stakeholders; however, it needs to be explored further as an independent topic. Based on social capital and social identity theories, we explore how online collaborative problem-based learning (PBL) effectiveness, relational quality, and social identity influence students' perceived PBL performance during learning activities. Based on the core elements of online coauthoring processes (i.e., platform, cocreation, and problem-solving), this study employs a holistic view of the coauthor to discuss the effects of understandability and completeness. This study also highlights the mediating impact of trust on students' social identity. Based on the responses of 240 students, the results support the proposed hypotheses using partial least squares analysis. The study's implications suggest guidelines to educators on how to enhance students' perceived PBL performance by using wiki technologies.