Based on Prieto's theory of communication we propose a didactic transposition of its concepts to establish an analytical look to understand certain discursive dynamics in classroom. The main concept of the theory to be highlighted is circumstantial indication sign. In the discursive activities, it is shown that the teacher serves up of circumstantial indications emission as interlocution tools to contextualize and encourage discussion with students, thus making them active participants in constructing knowledge. Making use of qualitative methodology, five science teacher classes were examined. In moments of discursive process of these classes, and between various semiotic emissions produced by the teacher, it is possible to identify certain types of signs qualified as circumstantial indications that present different characteristics and purposes in education. As we will see, the use of circumstantial indications is justified by its fundamental role in cognitive function and discursive context in order to enhance the learners' concepts.
Science Education; Semiotics; Signals; Discourse analysis