In Collaborative Design Studios (CDS), knowledge and information can be shared in discussions among students and instructors, while developing alternative solutions and the task coordination is achieved through the networked environment. In this study, a model called Evolutionary Design Collaboration (EDC) model is proposed as a framework for the collaboration of design courses, based on situatedness and reflective practice. A CDS including an information and a collaboration web site is conducted at the conceptual design level based on EDC model. The design critiques in redline files and the design diaries are evaluated by segmentation method. The redline files are analyzed with respect to ‘design abstraction’, ‘space and representation’ and ‘variables’ in problem domain and ‘micro-strategies’ and ‘design activities’ in design strategies. The analysis of design diaries is based on the behaviors and features of problem requirement and solution spaces. Moreover, two questionnaires are given at the end of CDS to identify usability problems in ease of use and user satisfaction. It is observed that the content of the critiques in CDS is similar to the content of the critiques of traditional design studios. The concept of situatedness is highly practiced as the new issues are introduced to the current design. Moreover, the active role assigned through collaboration to the students enhanced the design process. The high emphasis on the features of design solutions in design process is a similar approach to faceto-face communication. Finally, the results of the study showed the evolution generated by the reflections of participating courses during the collaboration through Internet.