This study investigated the role and process of self-directed reflective assessment (SDRA) enhanced by learning analytics to support pre-service teachers' (PTs') collective empowerment in a knowledge-building (KB) classroom. The participants were 43 second-year PTs from a compulsory course taught by a teacher who had 2 years' teaching experience. A comparison class of 47 PTs, taught by the same teacher and studying the same topics in a regular KB environment, also participated. Statistical analysis revealed significant differences in participation and domain understanding between the experimental class and the comparison class. Qualitative tracing of the SDRA group's online discourse indicated that the PTs were empowered and that their collective empowerment increased gradually over time. Analysis of the PTs' prompt sheets revealed that analytic-supported SDRA helped the PTs engage in collective decision making to choose and judge promising ideas, and in collective synthesis and "rise-above" of ideas, thus helping them engage in high-level collective empowerment. The findings have important implications for the design of technology-rich environments as metacognitive tools to support learners' empowerment, and they shed light on how teachers can use such tools to engage learners in metacognitive practices to increase their empowerment.