This paper addresses contributions that dynamic geometry systems (DGSs) may give in reasoning by contradiction in geometry. We present analyses of three excerpts of students’ work and use the notion of pseudo object, elaborated from previous research, to show some specificities of DGS in constructing proof by contradiction. In particular, we support the claim that a DGS can offer “guidance” in the solver’s development of an indirect argument thanks to the potential it offers of both constructing certain properties robustly, and of helping the solver perceive pseudo objects.
Reasoning by Contradiction in Dynamic Geometry / BACCAGLINI FRANK, ANNA ETHELWYN; Antonini, Samuele; Leung, Allen; Mariotti, Maria Alessandra. - ELETTRONICO. - 2:(2011), pp. 81-88. (Intervento presentato al convegno 35rd Conference of the International Group for the Psychology of Mathematics Education tenutosi a Ankara, Turkey nel 10-15 luglio).
Reasoning by Contradiction in Dynamic Geometry
BACCAGLINI FRANK, ANNA ETHELWYN;
2011
Abstract
This paper addresses contributions that dynamic geometry systems (DGSs) may give in reasoning by contradiction in geometry. We present analyses of three excerpts of students’ work and use the notion of pseudo object, elaborated from previous research, to show some specificities of DGS in constructing proof by contradiction. In particular, we support the claim that a DGS can offer “guidance” in the solver’s development of an indirect argument thanks to the potential it offers of both constructing certain properties robustly, and of helping the solver perceive pseudo objects.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
