In this paper, we report on the impact of four activities and two interviews on the organization of an introductory statistics course attended by future mathematics teachers at the University of Sao Paulo, Brazil. The activities were designed to enhance students' learning and collaborative knowledge construction, based on Vygotsky's Socio-Historical Theory. Data were collected in the course through the activities and the interviews. Analysis of the data suggests that the course improved students' initiative, collaboration and intentional action, as well as their attitude as future mathematics teachers. Quantitative results comparing 2013 with earlier offerings of the course are also discussed. The transformation discussed here could be applied in other introductory statistics courses, and may lead to practical pedagogical improvements.