This paper describes the development of a structured approach to evaluate the experiential and communication virtual learning environments (VLEs) that were designed specifically for use in the education of children with severe learning difficulties at the Shepherd School in Nottingham. Constructivist learning theory was used as a basis for an evaluation framework and analysis method to evaluate the behavior of the participants as well as the quality of the design of three different VLEs. From an observational field study of student-teacher pairs using the VLEs, eighteen behavior categories were identified as relevant to five of seven constructivist principles (Jonassen, 1994). The analysis of student-teacher behavior was used to provide evidence for (or against) how the VLEs met the constructivist principles. Results of this structured evaluation indicate that the three VLEs meet the constructivist principles in very different ways. This paper concludes with recommendations for appropriate design modifications.