The World Wide Web has increased extraordinarily the level of communications and collaborations among people via technology. As a consequence the use of computer systems in the teaching and learning processes has in the last few years moved to a new form of technology-supported instruction: web-based instruction. Web-based instruction is rapidly becoming one of the major sources to deliver courses to students. Besides the facility to communicate and collaborate with other students, one of the reasons for this fast increasing system of instruction delivery is its cost-effective.

Mathematics is a privileged subject to take advantage of the internet potential. It is a subject area with a recognized hierarchy of topics, which can be introduced with varying degrees of depth to a wide range of users. TextMat is an interdisciplinary academic project whose objective is the development (conception and implementation) of a maths web-based electronic textbook, i.e. an application with a multimedia database enhanced by instructional resources.

In Miller & Lu (2003) and Clerehan et al (2003), online learning is a social experience. The flexibility offered by online technologies support needs of different learners. In online learning research the study of new constructivist learning strategies is a vital issue. including the ones reported by Hughes and Daykin (2002), Sims (2003) Alexander et al (2003).

This paper concentrates in the theoretical framework underlying the pedagogical design of TexMat, a multimedia constructivist math learning environment. It comprises four main components: the tutorial- project space, the problem-project space, the collaboration space and the assessment-project space.

Underlying these components were produced cognitive tools with the purpose to support the learner¡¦s exploration, inference, reflection, social interaction to construct their knowledge. We shall made use of a virtual agent whose purpose is to guide the users in their learning, having in account their performances.