In this paper, we present some results about the develop of an on-line professional network called "MultiScopic" (multiple views on a phenomenon), trying to understand what are the tensions and limitations in this process of consolidation of an on-line community of educational practice analysis.

There are several previous studies analyzing the processes of creation, consolidation and expansion of virtual Communities of Practice (Barab, MaKinster and Scheckler, 2004; Bruckman and Jensen, 2004; Koch and Fusco, 2008; Riverin and Stacey, 2008), but the present case has a series of characteristics that we believe are worth being investigated.

MultiScopic is an on-line social network that involve to children of a primary school, their families, in-service physical education teachers, teacher training students, and their professors. In this on-line training and professional network, are exposed physical education lessons to primary school children.

The potential of the idea lies in the following aspects: For children involved is an opportunity to become aware of their action and progress. For their families is an opportunity to learn about the work that their children develop and participate in it. For teacher training students it is an opportunity to make contact with educational practice, exchange views with experienced professionals, and introduced themselves into the profession. For expert teachers is a space to share perspectives and enrich their analysis of practice. For the different groups of researchers allowed to complete perspectives, exchange procedures of analysis, and share their results.

Since we started in 2010 with MultiScopic, various working groups have been created in this network. We highlight some of the projects that are being developed:

-Get on to PE: Collaborative learning in courses of initial teacher training. Students analyze physical education lessons in Primary of which have been showing in MultiScopic. 

-Internationalmates: In this case, the collaborative groups are composed of students from different countries. 

- Welcomed the help: These are communities of practice formed by student teachers and experienced teachers. Students ask questions about their teaching during their internship period.

-(RE)Produce: This is a professional community of practice in which some teachers share their experiences, trying to apply to their context some of the practices exposed in MultiScopic.

In MultiScopic are involved professionals and students from Spain (Palencia, Segovia, Valladolid, Cáceres), Portugal, Argentina, Brazil and Chile.

In this paper we present part of the analysis we are carrying on the process of developing this professional and training network. To perform this analysis we start with the basic question about: How are the evolution and dynamics operating within the platform?

To illuminate this inquiry, we start with some concepts provided in other communities of practice experiences. Among them we cite the following:

- From Lewellen (2009) we take the idea of the structural contradictions between vertical and horizontal interests to analyze the tensions between developers and users of MultiScopic. In relation to the roles of power in a social network we rely on the work of Fombrun (2003) and to better understand the role of developers, stewardship and leadership, we start from the work of Koch and Fusco (2008), Kaulback and Bergtholdt (2008). To understand the tension between vertical and horizontal interests, also has helped us the tension described by Barab, MaKinster and Scheckler (2004) between diversity and coherence.

- About the motivations of the participants we started from the work of Bergtholdt Kaulback (2008). This work also gave us the idea of the tensions between task and relationship, and the concepts of ownership and time demands of members.

- To get a perspective on the dynamic nature of communities of practice and emerging needs of the participants, we start from the work of Barab, MaKinster and Scheckler (2004).

-Barab, S. A.; MaKinster, J. G. & Scheckler, R. (2004), Designing System Dualities. Characterizing an Online Professional Development Community. In S. A. Barab, R. Kling & J. H. Gray (eds.). Designing for Virtual Communities in the Service of Learning. Cambridge, Cambridge University Press, pp.53-90. -Bruckman, A. & Jensen, C. (2004), The Mystery of the Death of MediaMOO: Seven Years of Evolution o an Online Community. In K. A. Renninger & W. Shumar (eds.) Building Virtual Communities. Learning and Change in Cyberspace. Cambridge, Cambridge University Press, pp. 21-32. -Fombrun, C. J. (2003), Atribuciones de poder a través de una red social. En F. Requena Santos (ed.) Análisis de redes sociales. Orígenes, teorías y aplicaciones. CIS, Madrid, pp.399-416. -Lewellen, T. C. (2009), Introducción a la antropología política. Barcelona, Ediciones Bellaterra. -Plaza Fraguas, G. (2013), La comunidad de práctica virtual como herramienta en la formación inicial y continua del profesorado. Trabajo Fin de Grado, Grado en Educación Primaria. Universidad de Valladolid. http://91.109.245.159/~x/.txt/en/20/http/uvadoc.uva.es/bitstream/10324/4025/1/TFG-G=2520406.pdf -Kaulback, B. & Bergtholdt, D. (2008) Holding the virtual space. In C. Kimble & P. Hildreth (Eds.) Communities of practice: Creating learning environments for educators. Greenwich, Information Age, pp. 25-43 -Koch, M. & Fusco, J. (2008). Designing for growth: Enabling communities of practice to develop and extend their work online. In C. --Kimble & P. Hildreth (Eds.) Communities of practice: Creating learning environments for educators. Greenwich, Information Age, pp.1-23. -Stake, R. (2010), Qualitative Research: Studying how things work. Nueva York, The Guilford Press. -Riverin, S. and Stacey, E. (2008), Sustaining an Online Community of Practice: A Case Study. Journal of Distance Education, Revue de L’Éducation à Distance, 22 (2), 43-58. -Vena González, M. (2013), La comunidad de práctica virtual y su relación con la formación inicial y permanente del profesorado. Trabajo Fin de Grado, Grado en Educación Primaria. Universidad de Valladolid. https://uvadoc.uva.es/bitstream/10324/4034/1/TFG-G%20413.pdf