Analysis of a didactic proposal of Krasilchik with the semiotic focus of Duval

The biology´s teaching contains a series of representations, such as natural language, graphics, tables, diagrams, figures, which can be analyzed as registers of semiotic representation. Duval proposes a watchful eye on the teacher's students' difficulties, to perform conversion between different registers of semiotic representation. This study, exploratory, analyzes in the light of this theory such difficulties, within the simulation "Fluctuations in populations" proposed by Krasilchick (2004). To collect the data, we conducted a course with students of 2nd year of high school in Technical Environment. Of the two types of conversion semiotics, students had greater difficulties in conversions not congruent. Issues not congruent simulation proposal require the skills of explaining phenomena and the relationship between them and greater teacher attention at the time of change and coordination of the different registers of representation