The complexity of gear concepts, often misunderstood by young children, highlights the need for educational frameworks beyond simple play. To examine the effects of using the prediction, observation, and explanation (POE) model in building block activities, a true experimental design was implemented. A total of 49 preschoolers were randomly assigned to either an experimental group, which engaged with building blocks embedded with the POE model, or a control group, which followed a building instruction guide. Data were gathered through pretests, posttests, and two-week delayed tests administered to all participants. The theoretical framework for this study was based on the POE model, emphasizing the importance of prediction, observation, and explanation in the learning process. The results revealed that the POE model had positive impacts on fostering young children’s acquisition of gear concepts. Specifically, gear speed and gear direction were identified as the most challenging concepts for preschoolers to grasp. The results highlight the critical role of children's reflection in learning these concepts. The participants’ common naive conceptions about gear function, gear speed, and gear direction were identified. The implications of these results highlight the importance of incorporating reflective practices in early childhood education to enhance concept acquisition and address misconceptions. Keywords: science education, gear concepts, building blocks, alternative conceptions, early childhood education