2019-04-092019-04-092018-06MEDEIROS, Edilene Ferreira de; SILVA, Marcia Gorette Lima da; LOCATELLI, Solange Wagner. A argumentação e o potencial metacognitivo de uma atividade experimental baseada na POA (previsão-observação-argumentação). Amazônia: Revista em Ciências e Matemáticas, Belém, v. 14, n. 29, p. 27-42, jan-jun 2018. Especial Metacognição. Disponível em: http://repositorio.ufpa.br/jspui/handle/2011/10932. Acesso em:.2317-5125https://repositorio.ufpa.br/handle/2011/10932This research presents the metacognitive incidents of high school students when experiencing an experimental activity on photosynthesis and respiration based on Prediction-Observation Argumentation. The activity includes resumption of content, argument elements, and script guides. The experiment was selected aiming to apply knowledge of biology in a real context and to develop argumentative abilities. It consisted of placing a plant in two tubes containing water with phenolphthalein, one remaining in a darkroom and another one in the clearing. Students were asked to predict what would happen to each tube and compare with changes in the color related to pH. Eight students participated and the activity was carried out in cooperative groups, promoting discussion based on the perspective of participation in scientific practices. Specifically, metacognitive incidents were analyzed in the students' discourse when they justified their conclusions based on the data obtained in the experiment. The results indicated four categories of metacognitive incidents: confirmation, monitoring, positive change and negative change. In the discourses the students showed greater ability to observe experimental data and justify their conclusions after confronting their initial predictions with scientific knowledge. However, they present difficulties in arguing their explanations (metacognitive incident of negative change). We indicate that the activities promoting argumentation favor the selfregulation capacity of the learning processAcesso AbertoIncidentes metacognitivosPrevisão - Observação - Argumentação;Atividade experimentalFotossínteseRespiraçãoArtigo de Periódicohttp://dx.doi.org/10.18542/amazrecm.v14i29.5569