Résumé
In this paper we focus on the role of signs in students' perceptive processes underpinning the generalization of numeric-geometric patterns. Based on a videotaped Grade 9 classroom group activity undertaken by three students and framed by a cultural-semiotic theoretical perspective, we carry out a microgenetic analysis of an elementary form of mathematical generalization termed "factual". We present a detailed analysis of the dynamics between oral speech and gestures. Two main results are: the detection of intra-personal and inter-personal synchronizations between different semiotic systems; and the individuation of the key role played by objectifying iconic gestures. (Contains 5 figures.) [For complete proceedings, see ED496851.]