As an attempt to contribute to implementing scientific argumentation in classrooms, this study aimed to design an argumentation activity in which students were supported in engaging in the epistemic practices of scientific community. We reinterpreted prediction-observation-explanation strategy based on a resources perspective to acknowledge the role of students’ prior knowledge in their construction of arguments and to consider students as active participants with epistemic authority. This argumentation activity was intended to encourage students to construct scientific concepts with valid justifications based on their conceptual resources. Specifically, the activity consisted of three stages: (a) prediction with justification: predicting the result of the task and justifying the prediction; (b) observation: conducting the task to gather first-hand data: and (c) explanation with justification: reconstructing a valid argument with justification. We implemented this activity in classrooms to investigate its practical outcomes with students. The students were able to construct a rigorous argument on their own, evaluating and revising their arguments based on the resources they already possessed and the data they gathered in the observation stage. The results of this research shed light on how to develop scientific argumentation activities that support students as epistemic agents having the ability to construct scientifically rigorous arguments.