Abstract—Easy acquisition of information from the internet has made many college students become idle while working on their online inquiry learning assignments. As the insufficiency of metacognitive skills is one important factor that causes thinking idle during online inquiry, the application of Diigo social media is integrated with
metacognitive scaffolds to help improve metacognitive skills. The quasi-experimental design was used in this
research and the findings provided evidence that the experimental group performed significantly greater gains
compared with control group. Discussion and suggestions are provided in this paper. Keywords: e-learning; sicial media; online inquiry learing;