<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> ABSTRACT The work is focused on psychologists in modeling mental models that tutors and students build in communities of practice of Undergraduate Apprenticeship to analyse and solve problems of professional practice in different contexts of psychologists activities: Clinic, Social, Justice, Labor and Research. Unit of analysis is examined through a four dimensions matrix, to study cognitive change in professional modeling. Questionnaires about situation-problems were administered to 250 students of Psychology at the beginning and the end of Undergraduate Apprenticeship of Professional Practice during 2004 and 2005 at Buenos Aires University. Questionnaires about conceptions of development of students competences were administered to 45 Tutors during their work time in 2005. Results show diversity of competences built in different activity systems. The challenge is to widen social stages for the construction of heterogeneous and multidimensional profiles of professional skills.