Abstracts - Earli

implement or improve their teaching and educational programs in a number of environments, andto invite others to create work collaboratively and constructively with them.Portfolio’s mediation during co-assessment dialoguesWalther Tessaro, University of Geneva, SwitzerlandLucie Mottier Lopez, University of Geneva, SwitzerlandPortfolios are increasingly being used in teacher education. They are designed to promotemeaningful and authentic assessment in relevant contexts, as an "alternative assessment" favoringthe development of potentials for learning. They are frequently accompanied by reflectiveactivities and by interactions in different social formats with peers and supervisors, aimed at thenegotiation of meaning and the construction of shared understanding. Among the different types ofportfolios used in teacher education, we are interested in those whose purpose is to assess students’progress in the development of their professional skills. We propose to study, in a situatedassessment perspective, the relations between cultural and material tools, social interactions andassessment practices. More precisely, we investigate the possible forms of instrumental mediationprovided by portfolios to co-assessment exchanges. Our research was carried out in the context ofa program for future primary school teachers. Our paper presents an in-depth analysis of coassessmentdiscussions between the supervisor and eight students. A comparison is made betweenthe documents in the portfolio and the topics of the co-assessment interactions during theconference. Our analyses show that the supervisor refers more frequently to the portfolio duringthe conferences than the students. Three cases can be distinguished concerning the mediation ofhis assessment activity. The students explicitly refer to the portfolio in order to assess theirprofessional progression, in particular during in-service trainings. It appears that indirectmediation of the portfolio is seen as an interpretative background for co-assessment exchanges. Onthe basis of our results, we show the extent to which co-assessment interactions produce newinterpretations and appraisals of students’ professional skills in comparison with the selfassessmentsalready expressed by the students in their portfolios.How are science teachers’ conceptions about the Nature of Science constructed? Influence ofinitial preparation and professional environment.Fernando Flores-Camacho, CCADET-UNAM, MexicoLeticia Gallegos-Cazares, CCADET-UNAM, MexicoXochitl Bonilla-Pedroza, CCADET-UNAM, MexicoFlor Reyes-Cardenas, CCADET-UNAM, MexicoIn this investigation, we analyzed the impact that different factors such as schooling, professionalmilieu, readings, science popularization, and mass media have had in Mexican science teachers’conceptions about the nature of science. From a semi-structured interview with 53 teachers, 14categories were identified to describe science conceptions and its origins. These categories wereorganized around four main topics: Conceptions about science; Awareness of changes in theirconceptions; Transformation factors; and Teaching aspects. This research was conducted withteachers in 10 different states, so it includes teachers from different schools, backgrounds andcontexts. Results show that there are different factors which influence teachers’ conceptions aboutscience. These factors are more related to science popularization and mass media than to theirinitial preparation or professional environment.– 94 –